United States Region IV Final Report
Environmental September 30, 1 992
Protection Agency
^ South Florida Coastal
Water Quality
Characterization
Prepared for:
Water Quality Management Branch
U.S. Environmental Protection Agency
Region IV
345 Courtland Street, NE
Atlanta, GA 30365
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BP A 90 y/jj-fz. /o i *3
SOUTH FLORIDA COASTAL WATER QUALITY
CHARACTERIZATION
Prepared for:
U.S. Environmental Protection Agency
Region IV
Water Quality Management Branch
345 Courtland Street, NE
Atlanta, GA 30365
Prepared by:
Tetra Tech, Inc.
10306 Eaton Place, Suite 340
Fairfax, VA 22030
September 30, 1992
Contract No. 68-C1-0008
Work Assignment No. 0-36
LIBRARY
US EPA Region 4
Atlanta Federal Center
100 Alabama St., SW
Atlanta, GA 30303-3104
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TABLE OF CONTENTS
Section Page
List of Tables vii
List of Figures ix
Acknowledgments xi
Summary xiii
1. Introduction 1-1
2. Characterization and Description of the Study Area 2-1
2.1 Physical Location 2-1
2.1.1 Major Urban Areas 2-1
2.1.2 General Topography 2-1
2.1.3 Major Water Bodies 2-1
2.1.4 Habitats and Ecosystems 2-3
2.2 Climate 2-4
2.2.1 Annual Rainfall and Variation 2-4
2.2.2 Temperature Range 2-5
2.3 Demographics 2-5
2.3.1 Population and Trends 2-5
2.3.2 Major Industries/Employment 2-5
3. Circulation and Hydrology of the Straits of Florida 3-1
3.1 Velocity and Volume Transport of the Florida Current 3-2
3.2 Florida Current Meanders and Spin-Off Eddies 3-4
3.2.1 Meanders 3-4
3.2.2 Spin-Off Eddies 3-5
3.3 Tidal Influences 3-6
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TABLE OF CONTENTS, CONTINUED
Section Page
4. POTW Contributions to the Coastal Waters of Southeast Florida 4-1
4.1 Southeast Florida Outfalls Experiments 4-2
4.1.1 SEFLOE I 4-2
4.1.2 SEFLOE II 4-10
4.2 Facility Description and Effluent Characterization 4-10
4.2.1 Delray Beach 4-10
4.2.2 City of Boca Raton 4-10
4.2.3 Broward County North District 4-11
4.2.4 City of Hollywood 4-12
4.2.5 Miami-Dade North District 4-12
4.2.6 Miami-Dade Central District 4-14
4.2.7 Summary 4-17
4.3 Impacts from POTW Discharges 4-17
4.3.1 Effluent Plume Dynamics 4-17
4.3.2 Impacts on Water Quality 4-19
5. Nonpoint Source Contributions to Water Quality 5-1
5.1 General Land Use Patterns 5-1
5.2 Sources of Nonpoint Source Pollution 5-1
5.2.1 Urban Storm water Runoff 5-1
5.2.2 Agricultural Runoff 5-11
5.2.3 Marinas and Other Nearshore Industries 5-11
5.2.4 Mismanagement of Household Toxics 5-12
5.3 Runoff Characterization/Estimates of Mass Loadings 5-12
6. Conceptual Model of Ecosystem and Water Quality Interactions 6-1
6.1 Ecosystem Components and Processes 6-1
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TABLE OF CONTENTS, CONTINUED
Section Page
6.2 Status of the Major Ecosystems 6-2
6.2.1 Ecological Studies 6-3
6.2.2 Beach Renourishment Impacts 6-3
6.2.3 Fish Community Observations 6-6
6.3 Sources of Stress and Interactions Between Sources 6-6
6.4 Potential Effects of Water Quality Alterations
on Coastal Communities 6-11
6.4.1 Sediments 6-12
6.4.2 Nutrients 6-14
6.4.3 Toxicants 6-15
6.4.4 Oxygen 6-20
6.4.5 Light 6-22
6.4.6 Salinity 6-23
6.4.7 Pathogens, Herbivores, and Predators 6-23
6.4.8 Physical Damage and Changes in the Hydric Regime 6-25
7. Data Analyses 7-1
7.1 DECAL Model Application 7-1
7.2 Comparison of Relative Contributions to Water Quality
from POTWs and NPS Loadings 7-4
7.2.1 Comparative Relative Contributions 7-4
7.2.2 Comparative Absolute Contributions 7-4
8. Discussion 8-1
8.1 Limitations of This Study 8-1
8.2 Other Issues 8-3
9. References 9-1
Appendix A - SEFLOE Sampling Station Positions A-l
Appendix B - NPDES Permit Limits and Monitoring Data B-l
Appendix C - Contact List for South Florida Water Quality Study C-l
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LIST OF TABLES
Number Page
2-1. Population Trends in the Three Counties in the Study Area 2-6
3-1. Summary of Pompano Beach Current Data (9/6/68 to 10/5/68) 3-6
4-1. Surface Current Velocities and Direction for the Six POTWs
in the SEFLOE I Study 4-6
4-2. Characteristic Dilution Values with Range for the Six POTWs
in the SEFLOE I Study 4-9
4-3. Summary of Priority Pollutants Detected After Implementation of an EPA-
Approved Pretreatment Program at the Miami-Dade North District POTW 4-15
4-4. Summary of Priority Pollutants Detected After Implementation of an EPA-
Approved Pretreatment Program at the Miami-Dade Central District POTW .... 4-18
4-5. Yearly Average Effluent Concentrations for Each POTW of Concern 4-19
5-1. General Land Uses for Counties in the Study Area 5-1
5-2. Estimated Stormwater Pollutant Loads for South Florida 5-11
5-3. Estimated Loadings for Nonpoint Source Pollution
from Select Points in the Study Area 5-13
7-1. DECAL Input Data 7-3
7-2. Comparison of Point and Nonpoint Source Pollutant Loadings 7-9
8-1. Other Private and Public Wastewater Treatment Facilities
in Southeast Florida (City of Broward) 8-2
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LIST OF FIGURES
Number Page
1-1. The southeast Florida study area and locations of the six POTWs 1-2
3-1. Prevailing currents affecting the southeast coast of Florida 3-1
3-2. Cross-sectional view of the continental shelf off
Pompano Beach, Florida 3-2
3-3. Cross-sectional view of the Florida Current illustrating salinity
and temperature gradients 3-3
3-4. Cross-sectional view illustrating temperature and salinity gradients
off Pompano Beach, Florida, during a strong southward coastal flow
from a spin-off eddy 3-5
3-5. Qualitative model of a hypothetical spin-off eddy estimated
from drogue trackings 3-6
3-6. Current meter data off the coast from Boca Raton, Florida 3-7
4-1. Typical surficial plume configuration and triangle sector
approximation 4-5
4-2. Characteristic dilution curve for South Florida outfalls 4-8
4-3. Schematic of the Miami-Dade North District discharge pipe and diffuser 4-13
4-4. Schematic of the Miami-Dade Central District discharge pipe and diffuser 4-16
4-5. Schematic of wastefield from an open ocean outfall 4-20
4-6. Types of diffusers and their corresponding ZID configurations 4-21
5-1. General land use for Broward County 5-3
5-2. General land use for Dade County 5-5
5-3. General land use for Palm Beach County 5-7
5-4. Location of canal sites used to determine nonpoint source loadings 5-13
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LIST OF FIGURES, CONTINUED
Number Page
6-1. Beach renourishment projects for southeast Florida 6-4
6-2. Conceptual model of types and sources of stress to coral, mangrove,
and seagrass communities 6-7
6-3. Conceptual model of processes and effects relating to sedimentation
in southeast Florida coastal communities ¦ 6-13
6-4. Conceptual model of processes and effects relating to nutrient inputs
in southeast Florida coastal communities 6-16
6-5. Conceptual model of processes and effects relating to toxic inputs
in southeast Florida coastal communities 6-21
7-1. DECAL model results for Delray Beach, Boca Raton, and Broward POTWs .... 7-5
7-2. DECAL model results for Hollywood, Miami-Dade North, and Miami Central
POTWs 7-7
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ACKNOWLEDGMENTS
Dr. John Proni, National Oceanic and Atmospheric Administration, provided the SEFLOE I and
II data. Other water quality data and information were supplied by Dr. Richard Dodge, Nova
University; Mr. Alexander Stone, Project Reefkeeper, American Littoral Society; the South
Florida Water Management District; the Broward County Office of Natural Resource Protection;
the Metro Dade County Department of Environmental Resource Management; and the South
Florida Regional Planning Council.
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SUMMARY
The southeast coast of Florida is home to over 4 million year-round residents, with thousands
more people visiting each year. Consequently, the area has experienced rapid urban growth and
a corresponding increase in pollution. Several factors—physical, chemical, and biological
—influence water quality off the southeast coast of Florida. This study evaluates the relative
contributions of effluents from six sewage treatment plants (publicly owned treatment works, or
POTWs) and nonpoint sources of concern to the changes in water quality observed along this
coast. To better understand the potential impacts of point and nonpoint sources of pollution on
the resources of southeast Florida and to guide the application of screening models, a conceptual
model was developed to provide a graphical representation and descriptive summary of existing
knowledge concerning key ecosystem resources that may be impacted by changes in turbidity,
nutrients, and toxics. A deposition calculation (DECAL) model was then used to map the
transport of POTW effluents off southeast Florida.
Physical factors influencing water quality in the study area include the northward-flowing Florida
Current, located at the 24-meter (m) isobath along the continental shelf and transporting, on the
average, 32 million cubic meters per second (m3/s) at a mean flow velocity of 1.8 to 2.6 m/s.
Cyclonic spin-off eddies transport Florida Current water into the coastal areas, produce strong
current reversals, and advect heat and salt into the waters between the current and the shore.
Water in this area is also influenced by wind and tidal forces, resulting in lateral meanders and
cyclonic spinoff eddies.
A variety of environmental impacts, resulting from both human activities and natural processes,
have been identified in the study area. The biological resources within the area include the
mangroves and seagrass beds of Biscayne Bay and the coral hard-bottom communities of the bay
and offshore. These communities are influenced by the physical, chemical, and biological
processes occurring in the area. Large drainage canals serve as collection points for stormwater
runoff, some of which is not treated, and deliver significant volumes of fresh water to coastal
waters. These canals are the primary conduits for nonpoint source pollution to coastal areas.
Contaminants of concern include heavy metals and nutrients. The primary sources of point
pollution affecting the offshore water quality are the six POTWs discharging offshore within the
study area. Biological oxygen demand, total suspended solids, fecal coliform bacteria, and
residual chlorine are the primary pollutants in the effluent.
Comparisons of the relative contributions of point (POTW) and nonpoint sources of pollution
show that the POTW contribution is greater than the nonpoint contribution, in terms of pounds
of pollutant per million gallons of discharge. However, it should be noted that several
assumptions are associated with the nonpoint source pollutant loading, including the fact that
most nonpoint source discharges occur within the Intracoastal Waterway and Biscayne Bay and
pollutants may not reach the coral communities offshore.
Because of data gaps, especially in the areas of nonpoint source pollution loading and nutrient
loadings from point sources, this study should be considered preliminary in nature. It provides
direction for future studies of the impacts on water quality and the biota off the coast of southeast
Florida.
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1. INTRODUCTION
A variety of direct and indirect environmental impacts resulting from human activities, as well
as from natural processes, have been identified in the South Florida coastal area. These impacts
threaten the health of various South Florida ecosystems. Of particular concern are the coral reefs,
which are already under natural stresses at the northern limit of their range (Jaap, 1984). Direct
impacts to the reefs resulting from human activities include boating impacts (e.g., groundings,
propeller damage, anchor damage), diver impacts, overfishing, and dredging. Indirect impacts
include water quality degradation due to sewage outfalls, deep well injection, septic tanks, spills,
litter, and stormwater runoff (Grigg and Dollar, 1990). These indirect sources may be more
serious in terms of long-term effects because of the difficulties encountered in reducing or
eliminating excessive nutrients or toxic contaminants.
Currently, six sewage treatment plants (publicly owned treatment works, or POTWs) discharge
secondary-treated effluents toward the edge of the narrow continental shelf in southeast Florida,
where water depths begin to increase rapidly from 27 to 30 m (Figure 1-1). Although maximum
coral reef development occurs south and west of Cape Florida off the Florida Keys, tropical reef
biota also occur on octocoral-dominated hard-bottom communities from Miami north to Palm
Beach. The hard bottom in this transition zone is characterized by transecting ridges and troughs
and a large diversity of plant and animal life (also known as "live bottom"). Reef areas are
found at between 12 and 18 m and between 27 and 40 m. Beyond this depth the bottom is
mostly sandy and gently sloping.
Black band disease has been observed in corals in the vicinity of these discharges. This disease,
caused by the cyanobacterium Phormidium corallyticum, has been linked to nutrient enrichment,
high sedimentation rates, elevated temperatures, direct toxicity, and physical damage (Peters,
1992). Excessive nutrients may also stress coral reefs by promoting the growth of fleshy algae,
outcompeting corals and other sessile benthic organisms. Increased phytoplankton and related
eutrophication problems (deposition of suspended solids) may reduce light penetration (Tetra
Tech, 1983). Because the corals derive a portion of their nutrition from mutualistic symbiotic
algae, known as zooxanthellae, living within their tissues, reduced light levels that decrease
photosynthesis can also affect the general health of the coral.
This report evaluates the relative contributions of effluents from the six POTWs and nonpoint
sources of concern to changes in water quality observed off southeast Florida from Miami to Fort
Lauderdale. Existing effluent data on nutrients, toxics, suspended solids, and other conventional
pollutants were obtained from the six POTWs to characterize pollutant mass loadings. The most
recent physical dispersion and environmental impact data from the Southeast Florida Outfalls
Experiment (SEFLOE) were obtained from the National Oceanic and Atmospheric
Administration's Atlantic Oceanographic and Meteorological Laboratory. Data were also
collected to characterize and estimate mass loadings from nonpoint sources along the coast in this
region. Oceanographic data were compiled and evaluated to characterize the extent and potential
causes and sources of environmental impacts observed in nearshore marine communities.
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STATE OF FLORIDA
Figure 1-1. The southeast Florida study area and locations of the six POTWs.
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A conceptual model was prepared to synthesize and integrate the information on ecosystem
components, physical and chemical processes, and interactions between these processes and
organisms in the nearshore communities. This conceptual model was used to guide the
application of a screening-level model, DECAL (deposition calculation), to better quantify the
relative contribution of pollutant loadings from the widely dispersed multiple point and nonpoint
sources and to account for possible overlapping effects and oceanographic transport influences.
The DECAL model was first used to estimate plume dispersion and the sediment deposition
footprint around each POTW to better address possible impacts of organic sediments and toxics
released from the point sources on the coral communities off southeast Florida. Most of the
SEFLOE II data needed to conduct these model simulations were not available in time to be
included in this report. As a result, only one DECAL run, based on information from the
Broward outfall, is presented here. A DECAL model simulation was also planned to examine
the nonpoint source contributions from coastal canals for comparison with the POTW
contributions. However, important information necessary for the use of this model (suspended
sediment concentration data) could not be located.
This report is divided into several chapters, which address the study area (Chapter 2), the
circulation and hydrology of the Straits of Florida (Chapter 3), POTW contributions (Chapter 4),
nonpoint source contributions (Chapter 5), the conceptual model (Chapter 6), results of the model
simulation and analyses of available data (Chapter 7), and other related issues (Chapter 8). The
appendices contain additional information on SEFLOE sampling stations, NPDES data for the
POTWs, and a list of contact persons from whom information and data for this report were
obtained.
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2. CHARACTERIZATION AND DESCRIPTION OF THE STUDY AREA
This section describes the principal geographic and demographic features of the southeast coast
of the Florida peninsula. Knowledge of these features is essential to an understanding of the
water quality problems of this area.
2.1 Physical Location
The study area is bounded generally by Delray Beach, Florida, to the north (26°30' north
latitude) and Miami/Key Biscayne, Florida, to the south (25°40' north latitude). The area
covers approximately 85 km of the South Florida coast and extends to the approximate axis of
the Florida Current (as noted in NO A A nautical chart 11460).
2.1.1 Major Urban Areas
The study area is a rapidly urbanizing area that includes the Fort Lauderdale and Miami
metropolitan areas. This area sustains a population of approximately 4 million people. The
primary industries in the area are service-related; tourism and trade play a key role in the
economy. Within the study area are two seaports that are major cargo and cruise ship
destinations: Port Everglades and the Port of Miami. The Fort Lauderdale/Hollywood and
Miami International Airports reported 6.3 million air visitors in 1988 (Florida Department of
Commerce, 1988). There is a concentration of seasonal visitors, especially in the coastal area.
This tourism, along with the increase in the permanent population, has led to overbuilding along
the shorelines, contributing to the degradation of nearshore water quality from urban runoff and
other impacts.
2.1.2 General Topograph y
The land area is relatively flat, with elevations ranging from sea level to approximately 6 m
above sea level. The highest point is in Broward County along the Pine Island Ridge. Another
ridge, the Atlantic Coastal Ridge, is an ancient dune system that runs generally parallel to the
shoreline through Palm Beach, Broward, and Dade Counties. This ridge was the area of initial
development in Sopth Florida because it provided a dry area on which to build.
2.1.3 Major Water Bodies
South Florida is historically part of the vast Everglades wetlands system. Most of the areas west
of the Atlantic Coastal Ridge were once under water at least part of the year. Areas east of the
coastal ridge were wetlands transitioning into a beach habitat. As the area grew, the need for
flood control and potable water delivery to wellfields became apparent. During the first half of
this century, the U.S. Army Corps of Engineers dug canals to drain the land for urban and
agricultural development and to deliver water to coastal wellfields. All of these canals drain to
tide, with a few also backpumping to the constructed Water Conservation Areas in western
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Dade, Broward, and Palm Beach Counties. These canals, often referred to as the primary
drainage system, are now maintained by the South Florida Water Management District and are
the ultimate receiving waters for stormwater runoff not retained on site. Because of this role,
they are a major contributor to near coastal and offshore nonpoint source pollution.
The Intracoastal Waterway (ICW) extends the entire length of the study area. In the Palm Beach
County and Broward County portion of the study area, the ICW consists of a wide channel
dredged on the landward side of the beach system. In Dade County it is part of Biscayne Bay.
Because of the large volume of boat traffic in the ICW, it is a potential significant nonpoint
source of pollution.
There are six inlets in the study area: Hillsboro Inlet, Port Everglades Inlet, Haulover Inlet,
Norris Cut, Bear Cut, and Government Cut. These features play an important role in near shore
circulation patterns and may be a conduit for nonpoint source pollution discharges to coastal
waters; however, little information exists to confirm this possibility.
The study area includes the northern portion of Biscayne Bay, a shallow 71,225-hectare (ha)
subtropical lagoon. The northern part of the Bay has experienced severe water quality problems
over the years. The Miami River and Little River are major sources of poor-quality water in
Biscayne Bay. The following paragraphs provide general information regarding the water
quality of northern Biscayne Bay and its contributing tributaries.
• Dumfoundling Bay - Dumfoundling Bay receives runoff from surrounding urban and
industrial areas. Water quality problems include stagnant areas associated with dead-
end canals, sewage contamination, low dissolved oxygen, and contamination from
these PCBs and other anthropogenic chemicals (SFWMD, 1988).
• North Bay - The primary water quality problem in this part of the bay is turbidity
from scoured shorelines and dredged areas. High levels of phthalic acid esters
(PAEs) are found in North Bay (SFWMD, 1988). This is an area of heavy marina
activity, which includes the Port of Miami, a potential source of contamination from
spills and leaching of antifouling paints. As mentioned previously, the Miami River
and Little River discharge into northern Biscayne Bay. They have been identified as
sources of sewage contamination and other pollutants from upland land uses. The
Little River has a history of poor water and sediment quality with high levels of lead
and other trace metals, nutrients, coliform bacteria, turbidity, and hydrocarbons that
may indicate persistent sources (SFWMD, 1988).
In spite of its water quality problems, northern Biscayne Bay also contains some
unique environmental resources. Bird Key has one of the largest pelican rookeries
along the southeast coast of Florida. The largest and healthiest seagrass bed in north
Biscayne Bay is found between the Julia Tuttle and 79th Street Causeways. The
preservation of these areas is critical to the health of this part of Biscayne Bay.
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• Miami River - The Miami River has been used historically as a waterway for
commercial and marine commerce. Water quality has been sampled in the river since
1984 and consistently violates coliform standards for Florida Class III water bodies.
The water is turbid due to the effects of shipping, and it has low levels of dissolved
oxygen (SFWMD, 1988). Acute pollution problems are the result of sewage pollution
and stormwater discharges. Chronic problems include metals, tributyltin, and organic
chemical contamination. Because of sediment accumulation in the river, many areas
are often disturbed by ships traveling on the river, resuspending contaminated
sediments. An additional source of contamination may be contaminated groundwater
from Miami International Airport.
2.1.4 Habitats and Ecosystems
The following discussion is a general overview of the habitats and ecosystems in the study area.
A more detailed discussion is included in the conceptual model. More information on the
structure, function, and composition of these nearshore communities of the South Florida basin
has been compiled by Continental Shelf Associates, Inc. (CSA, 1990).
Mangroves
Mangroves perform important environmental functions, including filtering upland runoff,
protecting inland areas during storms, and providing habitat for marine organisms. Historically,
South Florida was fringed with mangrove swamps. Within the study area these have been
replaced by urban development. The Metro Dade County Planning Department (1986) has
estimated that of the 18,615 ha of mangroves in Dade County in 1900, 4,249 ha exist today.
Within the study area, there are only small pockets of mangroves, the largest of which are located
in West Lake in Hollywood and in the Oleta River in North Miami Beach.
Seagrasses
Seagrass beds serve as nursery grounds and habitat to several hundred species of marine
organisms. Their presence indicates good water quality with minimal turbidity. As indicated
above, the most extensive seagrass bed in the study area is in north Biscayne Bay between the
Julia Tuttle and 79th Street Causeways. North of Biscayne Bay, the coverage drops off rapidly.
The shifting sand beaches that result from the high-energy coastal environment provide an
unstable substrate. Throughout the study area seagrasses are usually found only in small pockets
that are protected from wave energy (Zieman, 1982).
Coral and Other Benthic Communities
Within the study area, there is an extensive coral system, primarily soft corals and stony corals.
These occur in ridges and patches and are not like the spur-and-groove formations that occur
south of Miami and in the Florida Keys. In general, southeast Florida reefs are considered relict
and not in an active growth stage, but they are veneered by a variety of living reef organisms
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(Jaap, 1984; Dodge, 1987). From Palm Beach to Cape Florida, elements of tropical biota become
increasingly dominant from north to south. Acroporapalmata was once an important reef builder
in this area, but ceased building reefs about 4,000 years ago. Three terraces have been
recognized, with a back reef consisting of one terrace at 100 meters offshore in 4 to 5 m of water
and a second terrace at approximately 800 m offshore at a 7- to 10-m depth. The third terrace
reef platform is at a depth of 16 to 20 m. The forereef region is composed of a flat plain of
rubble at a 30- to 50-m depth (Goldberg, 1973). The third terrace is biologically and
geologically the most well-developed and occurs from 900 to 1200 m offshore. The appearance
and location of the terraces vary along the coast. Today, only a few isolated reef communities
appear north of Fort Lauderdale (Jaap, 1984). Coverage by hermatypic (reef-building) corals is
low when compared to the Florida Keys and Caribbean region; however, the fauna form a
valuable component of community structure and provide the principal means by which material
is actively incorporated into the reef framework. The communities also provide relief, which in
turn provides habitat for a variety of marine organisms (Dodge, 1987).
Coral communities are sensitive to increased turbidity and other perturbations. Because the study
area is at the northern limits of their range, they are more susceptible to adverse impacts and
stresses, both natural and human-induced. Natural stresses include temperature fluctuations and
bacterial diseases. Examples of human-induced stresses include boat anchors, boat and ship
groundings, physical contact from divers, and nutrient and pesticide loadings from upland land
uses, as well as increased turbidity from offshore dredging, beach renourishment, and stormwater
runoff.
2.2 Climate
The climate of South Florida is characterized as subtropical marine and is strongly influenced by
the adjacent marine environment.
2.2.1 Annual Rainfall and Variation
Typically, South Florida receives 152 cm of rain annually. There are two distinct "seasons": the
rainy season from June to November and the dry season from December to May. The rainy
season is characterized by daily afternoon thunderstorms and an average monthly rainfall of 15.7
cm. This is the major period of freshwater flow to the coastal areas. During the dry season, there
is minimal rainfall, with a monthly average of 5 cm (South Florida Regional Planning Council,
1991). The area is also within the zone subject to storms and hurricanes during the summer and
fall months. These can have short-term impacts such as large flows of fresh water to the coastal
environment and increased turbidity in coastal waters due to the movement of these large
volumes of water and sediment resuspension by increased wave action. The construction of the
primary drainage system has led to incidents of "slugs" of fresh water being released to the
coastal environment instead of the historic sheet flow. These slugs can carry loads of pollutants
from nonpoint sources and can cause a rapid change in the salinity of an area. This occurrence
is discussed in greater detail in Chapter 5.
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2.2.2 Temperature Range
The annual temperature range for South Florida is from approximately 70 °F in the winter to
90 °F in the summer. There are temperature variations, depending on meteorological
occurrences.
2.3 Demographics
Land uses within the study area are primarily urban in nature. Since the early 1900s, with the
extension of the Florida East Coast Railway to West Palm Beach and Miami, the area has
experienced rapid growth. Favorable climate and plentiful natural resources have made the area
very attractive not only to vacationers, but also to permanent residents.
2.3.1 Population and Trends
Table 2-1 illustrates the estimated increases in population in the study area since 1950 and the
projected growth through the year 2000.
Urbanization started at the coast and along river banks and has moved west. Because a vast
majority of the area was Everglades wetlands, initial development occurred on higher areas that
were not prone to flooding. To minimize flooding and make land more suitable for agricultural
and urban development, canals were dug to drain the wetlands to the west. Most of these canals
drain to tide, carrying the pollutants associated with urban and agricultural development to the
coastal areas.
2.3.2 Major Industries/Employment
Tourism is the major industry in South Florida. The warm climate and unique natural resources
are a draw for both domestic and foreign tourists. Tourism, however, has led to the exploitation
and degradation of natural resources.
The coastal waters off southeast Florida are one of the most densely used recreational bodies of
water in the country and are adjacent to the only living coral reef in the continental United
States. These two factors make environmental impacts to these coastal waters a major concern
in terms of protecting human health and delicate biological communities. In an area where the
beaches and the recreational fishing industry are the major draws for the tourist industry,
contamination of the waters could have disastrous effects on local economies.
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Table 2-1. Population Trends in the Three Counties in the Study Area
Year
Broward
Dade
Palm
Beach
Total
1950
83,933
495,084
224,688
693,705
1960
333,946
935,047
228,106
2,497,099
1970
620,100
1,267,792
348,993
2,236,885
1980
1,018,257
1,625,509
576,663
3,220,629
1990
1,255,488
1,937,094
863,518
4,056,100
2000
1,467,554
2,183,841
1,104,136
4,755,531
%
Increase
1950-2000
1,648
341
863
585
SOURCE: Florida Census Estimating Conference, Population and Demographic Forecast (Spring 1991) -compiled by the South
Florida Regional Planning Council, 1992.
Most Significant Factors Affecting Water Quality
• Over 4 million people live in the Miami/Fort Lauderdale area, and
thousands of others visit the coast each year. Tourism and the increase
in the permanent population have led to rapid development and water
quality impacts from urban runoff.
• Canals used to drain the land for urban and agricultural development
earlier in this century receive stormwater runoff and contribute to the
near coastal and offshore nonpoint source pollution.
• Other contributors of nonpoint source pollution include boat traffic in
the Intracoastal Waterway and inlets. The Miami River and Little River
are major sources of poor-quality water in Biscayne Bay.
• In the rainy season (June to November), rainfall averages 15.7 cm per
month, with additional storms and hurricanes that cause increased
turbidity and reduced salinity, as well as increased loads of nonpoint
source pollutants.
2-6
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3. CIRCULATION AND HYDROLOGY OF THE STRAITS OF FLORIDA
The North Equatorial Current, which represents the southern portion of the anticyclonic gyre of
the North Atlantic Ocean, joins the Guiana Current (the northern section of the South Equatorial
Current) to penetrate the Caribbean through the openings between the Lesser Antilles and the
Greater Antilles (Tchernia, 1980). These openings consist of the Dominica Passage, the St. Lucie
Channel, the Anegada and Virgin Islands Passages, and the Windward Passage. Shortly beyond
the Yucatan Channel, the current turns sharply to the right, entering the Straits of Florida, to
become the Florida Current (Figure 3-1). The Florida Current is joined by the Antilles Current
at the northern end of the Florida Channel to form the western meridian segment of the North
Atlantic anticyclonic gyre.
Figure 3-1. The prevailing currents affecting the southeast coast of Florida (adapted from
Tchernia, 1980).
3-1
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The combination of the east winds and narrowness of the Straits of Florida causes an
accumulation of water in the northern Gulf of Mexico, resulting in a sea level on the west coast
of Florida 19 cm higher than that on the east coast. The outflow caused by the geostrophic
potential follows the Florida Channel, the only deep channel connecting the Gulf of Mexico to
the Atlantic Ocean. This channel is 648 km long and runs east-west to its halfway point, where
it turns south-north between Havana, Cuba, and the Dry Tortugas. The channel is 130 km wide
at this point and narrows to 74 km, with a maximum depth of 800 m (Tchernia, 1980; King and
O'Brien, 1971). The channel widens to 148 km at the northern exit, located between the east
coast of Florida and Little Bahama Bank.
3.1 Velocity and Volume Transport of the Florida Current
The continental shelf off the southeast Florida coast is narrow, ranging from 1.9 km off Boca
Raton to between 5.6 and 6.5 km off Miami (Lee and McGuire, 1972; Lee and Mayer, 1977).
There is a 6-m ridge at the outer edge of the shelf, in 24 m of water (King and O'Brien, 1971;
Figure 3-2), from which the bottom gently shoals at a ratio of 20:1 to the shore (Lee and
Figure 3-2. Cross-sectional view of the continental shelf off Pompano Beach, Florida
(adapted from Lee and McGuire, 1972).
3-2
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McGuire, 1972). The western edge of the
Florida Current follows a sharp discontinuity
near the ridge that separates the shelf from
the depths. The strongest nearshore current
between Delray and Miami is only 24 km
offshore. Mean flow velocities for the
Florida Current range from 1.8 to 2.6 m/s
(King and O'Brien, 1971; Tchernia, 1980).
Sharp horizontal gradients in salinity, current
speed, and water color are characteristic of
the western edge of the Florida Current.
Water volume transport of the Florida
Current is known to fluctuate on tidal and
annual time scales (Lee and Williams, 1988).
Mayer et al. (1984) have reported tidal
fluctuations on the order of +1.5 million
cubic meters per second (m3/s). Seasonal
fluctuations of +4 million m3/s are
asymmetrically distributed about a mean
northward volume transport of approximately
32 million m3/s, with maximums in the
summer and minimums in the fall (Schmitz
and Richardson, 1968; Niiler and Richardson,
1973; Larsen and Sanford, 1985; Molinari et
al., 1985; Leaman et al., 1987). Schmitz
and Richardson (1968) estimated the net
fluctuation bound for the steady-state volume
transport to be ± 12 million m3/s.
Florida
(Fbwty Rocks)
w
Bahamas
(Bimini 13
W
- 900
- 900
80 Km
Figure 3-3. Cross-sectional view of the Florida
Current illustrating salinity and temperature
gradients (Tchernia, 1980).
Water volume transport can be significantly
affected by local along-channel winds created by synoptic weather events (Lee and Williams,
1988). Northerly winds cause an increase in volume, and southerly winds cause a decrease.
Northward winds create an easterly Ekman transport, which establishes a westward barotropic
pressure gradient (the height of the water is greater on the westward side) that drives the
northward geostrophic transport (Lee et al., 1985). The fluctuating wind stress can also produce
surface onshore/offshore Ekman transport (downwelling/upwelling), which causes deep cross-
shelf water movement over the steep bottom topography (Brooks, 1975). These movements
advect warmer waters off the slope, acting as a mechanism for the redistribution of water masses
and nutrients. The barotropic perturbations and cross-channel interior flows cause a steepening
of the pycnocline, a distinct vertical density gradient (Figure 3-3). The combination of
barotropic perturbations and steepened isopycnals is advected northward. This baroclinic
instability (friction) converts mean potential energy to eddy kinetic energy and then back to the
mean flow, thereby providing a mechanism for meander and eddy growth downstream (Lee and
Mayer, 1977; Lee et al., 1985; Lee and Williams, 1988).
3-3
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3.2 Florida Current Meanders and Spin-Off Eddies
Meanders and eddies are an integral part of the Florida Current and are known to occur all along
the southeastern United States from the Straits of Florida off Miami to near Cape Hatteras (Von
Arx et al., 1955; Webster, 1961; Duing, 1975; Lee, 1975; Duing et ah, 1977; Lee and Mayer,
1977; Bane and Brooks, 1979; Brooks, 1979; Legeckis, 1979; Pietrafesa and Janowitz, 1980;
Brooks and Bane, 1983; Lee and Atkinson, 1983; Lee and Waddell, 1983; McClain et al., 1984;
Zantopp et al., 1987). Such changes in current patterns were described first by Pillsbury (1890)
off Key West and Miami and were addressed later by Parr (1937).
3.2.1 Meanders
Meanders are low-frequency current fluctuations that appear as northward-traveling waves
(Legeckis, 1979; Bane and Brooks, 1979; Lee and Mayer, 1977) where the westward
displacement of the Florida current appears as the "crest" of an onshore meander. More
specifically, a meander is a northward-moving barotropic wave superimposed on the mean
baroclinic profile of the current (Duing, 1975), with periods ranging from 2 days to 2 weeks
(Lee, 1975; Lee and Mayer, 1977; Lee et al., 1985).
Schmitz and Richardson (1968) reported horizontal meanders having a 1-week time scale and 5-
km amplitudes. A 191-day record of transport collected east of Foley Rocks (just south of
Miami) indicated periodicities ranging from 5 to 10 days (DeFerrari, 1970). Duing (1975)
recorded current modulations on 4- to 6-day time scales, estimated wavelengths of 160 and 240
km, and a phase speed of approximately 50 cm/s. Webster (1961) located a 7-day meander of
the Florida Current off Onslow Bay that had an amplitude of 10 km. Like the results
documented by Lee and Mayer (1977) and Duing et al. (1977), this meander was correlated with
onshore winds from north-south pressure variances that lagged by 4.5 days.
Fluctuations in physical parameters such as temperature and salinity may be used as indicators
of current meanders. Temperature records from the waters off Miami show several-day
oscillations with amplitudes of 2 to 3 C (Mooers and Brooks, 1974, 1977). Salinity transects
conducted offshore from Pompano Beach indicate a subsurface core of high-salinity water that
ranges from 36.2 to 36.6 parts per thousand (ppt.) (Lee and McGuire, 1972). This represents an
intrusion of the Florida Current into coastal waters and an east-west meander of 1.9 to 3.7 km
(Figure 3-4).
Meanders cause large fluctuations of current speed and direction of shelf waters, thereby creating
instabilities in the lateral shear region of the Florida Current (Lee and McGuire, 1972).
Upwelling occurs in the meander wave troughs between the offshore displaced front and the shelf
break (Zantopp et al., 1987). The combination of these effects is thought to produce cold,
cyclonic (anticlockwise) spin-off eddies that are entrained in the coastal waters (Figure 3-5) and
move northward with the parent wave (Lee et al., 1981; Lee and Atkinson, 1983; Brooks and
Bane, 1983; McClain et al., 1984). These cyclonic vortices are thought to occur on a continual
3-4
-------
basis, thereby creating a zone of
divergence and upwelling along
the eastward side of the current
(Baranov, 1967).
3.2.2 Spin-Off Eddies
Lateral meanders moving
northward can transfer momentum
onto the shelf and produce current
data that indicate the passage of an
eddy (circular current) when
measured from a fixed location.
They cannot, however, transfer
heat and salt (Stommel, 1965).
There is no exchange of water
mass across the front from a
meander. However, cyclonic
(counterclockwise) eddies transport
Florida Current water into the
coastal region and entrain coastal
waters into the Florida Current.
Strong southward flows and
perturbations of high-salinity (s
36.4 ppt.) water are produced, as
well as isotherms that either are
horizontal or deepen toward the
west (DeRycke and Rao, 1973).
The characteristics of the Florida
Current, most notably significant
turbidity decreases and a deep blue
coloration, accompany the
southward-moving extrusion (Lee,
1975).
Figure 3-4. Cross-sectional view illustrating temperature
and salinity gradients off Pompano Beach, Florida, during
a strong southward coastal flow from a spin-off eddy (Lee,
1975).
Cyclonic eddies are typically detected from current data that indicate the occurrence of current
reversals. Nine months of current data off Boca Raton indicated 163 reversals occurring in 270
days, or a reversal approximately four times a week (Lee and McGuire, 1972). The v component
(north-south) series was to the south 31 percent of the time with a mean velocity of 20 cm/s and
to the north 62 percent of the time with a mean velocity of 23 cm/s. The u component (east-
west) series was to the east 47 percent and to the west 46 percent, and both directions had
equivalent mean velocities of 8 cm/s. The variability of these data, which are summarized in
Table 3-1, was extremely high, with standard deviations ranging from two to four times the
mean. These reversals were concluded to be cyclonic eddies with currents moving southward
3-5
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at the rate of 10 to 77 cm/s, widths of 1.9 to 11.1
km, and downstream dimensions two to three
times greater than the width. The duration of the
current reversals varied from a few hours to 60
hours. Eddies can also be detected by strong
current reversals accompanied by an advection of
heat and salt into the "coastal strip," the thin band
of coastal water between the Florida Current and
the shore (Duing and Johnson, 1971).
The rate of northward movement of these eddies
can be affected by seasonal events. Niiler and
Richardson (1973) reported an average velocity in
July (20 cm/s) that was three times the average
velocity recorded in March and April (7 cm/s).
The increased volume transport of the Florida
Current during the summer is thought to be the
cause of seasonal differences. Lee (1975)
collected satellite imagery that suggests that the
formation of edge eddies may be directly
attributed to "Ford bands" (Ford et al., 1952)
consisting of relatively fresh, cool water along the
Gulf Stream (Florida Current) front. The intense
lateral shear found at the boundary regions may
create sufficient barotropic instability to produce
short-lived eddies.
3.3 Tidal Influences
Figure 3-5. Qualitative model of a
Typically, the movement of shelf waters is hypothetical spin-off eddy estimated from
dominated by wind and tidal forces; however, the drogue trackings (Lee, 1975).
Table 3-1. Summary of Pompano Beach Current Data (9/6/68 to 10/5/68)
Quadrant
(Degrees)
Current
Direction
Number of
Observations
% of Total
Observations
Mean Velocity for
Quadrant (Knots)
Mean Standard
Deviation for
Quadrant
316-45
North
4939
59.1
0.44
0.216
46-135
East
494
5.9
0.34
0.192
136-225
South
2331
27.9
0.40
0.202
226-315
West
588
7.0
0.23
0.123
SOURCE: King and O'Brien, 1971.
u" ;f '/
'JpQP- rvCftGi flQE5 ao#w
HYPOTHETICAL
FLORIDA CURRENT
SPIN-OFF EDDY
3-6
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coastal waters of the southeast coast of Florida are unique because of the extreme narrowness of
the continental shelf (1 - 3 km) and the close proximity of the Florida Current (Lee and McGuire,
1972). The high current variability of the coastal waters off Boca Raton and Pompano Beach
is governed primarily by small-diameter, cyclonic edge eddies (Lee, 1975), with semidiurnal and
diurnal tidal currents contributing only 10 to 25 percent to the variability (Lee and Mooers, 1977;
Kielman and Duing, 1974; Smith et al., 1969). Harmonic tide analysis of the 10 major tidal
constituents showed the amplitude of the diurnal components to be equal in magnitude to that
of the semidiurnal components, even though the tidal changes in sea level in the Straits of Florida
are semidiurnal (Lee and McGuire, 1972). There is a longitudinal diurnal standing wave joining
the Gulf of Mexico with the Atlantic Ocean, with a node located near Miami (Zetler, 1968). The
current meters were located near the node, thereby recording diurnal currents without diurnal
changes in sea level.
A tide prediction model was developed by recombining the amplitude and phase of the 10 major
tidal constituents (Schureman, 1958). The difference between predicted and actual tidal currents
was termed the residual. When 1-hour averages are graphed (Figure 3-6), the actual and residual
curves are almost identical, indicating only a small tidal influence (Lee and McGuire, 1972).
Average currents fluctuated around the mean by 40 to 70 percent, and only 5 percent of this
fluctuation was attributed to the tides. It was concluded that tidal currents play an insignificant
role in the circulation of coastal waters off southeast Florida.
Figure 3-6. Current meter data off the coast from Boca Raton, Florida (Lee and McGuire, 1972).
3-7
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The six ocean outfalls in this study discharge into a narrow strip of coastal water located at or
just beyond the 24-m isobath. The circulation of the coastal waters off southeast Florida is
dominated by lateral meanders of the Florida Current and cyclonic spin-off eddies. Because of
these dominating forces, the effluents from the six POTW facilities are discharged into the coastal
waters, the western edge of the Florida Current, or the western portion of a cyclonic eddy. The
direction of these currents is primarily north-south; however, a sizable western component, with
a mean velocity of 8.2 cm/s, does occur (Lee and McGuire, 1972). The residence time of coastal
waters is on the order of 1 week (Lee and McGuire, 1972; Lee, 1975).
Most Significant Factors Affecting Water Quality
• The Florida Current flows northward along a ridge situated at the 24-m
isobath on the edge of the continental shelf. The strongest nearshore
current between Delray Beach and Miami is only 24 km offshore.
• The mean flow velocity of the Florida Current ranges from 1.8 to
2.6 m /s and has a mean volume transport of 32 million m7s.
Maximum transport occurs in the summer and minimum values are
seen in the fall.
• Low-frequency horizontal current fluctuations appear as northward-
traveling waves with periodicities ranging from 5 to 10 days,
wavelengths of 160 to 240 km, and amplitudes ranging from 5 to
10 km.
• These lateral meanders produce cyclonic (counterclockwise) spin-off
eddies, which transport Florida Current water into the coastal region
and entrain coastal waters into the Florida Current. Eddies produce
strong current reversals and advect heat and salt into the "coastal strip,"
the thin band of coastal water between the Florida Current and the
shore.
• Typically, shelf waters are dominated by wind and tidal forces;
however, the continental shelf off the southeast coast of Florida is very
narrow, thereby producing a unique situation. The circulation of the
coastal waters off southeast Florida is dominated by lateral meanders
and cyclonic spin-off eddies.
• The residence time of the coastal waters off southeast Florida is
approximately 1 week.
3-8
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4. POTW CONTRIBUTIONS TO THE COASTAL WATERS
OF SOUTHEAST FLORIDA
Six municipal wastewater treatment facilities discharge primarily secondary-treated residential
wastewater into the coastal waters of southeast Florida. All six outfalls are located at the 27-m
isobath or deeper and discharge into the western edge of the Florida Current, the western edge
of a northward-moving cyclonic eddy, or coastal waters (residence time is approximately 1
week). The coastal waters off southeast Florida are one of the most densely used recreational
bodies of water in the country and contain octocoral-dominated hard-bottom communities that
attract a wide array of tropical coral reef organisms despite.being located at the northernmost
limit of the range for reef biota. These two factors make these coastal waters a major concern
in terms of protecting human health and delicate biological communities. In an area where the
beaches and the recreational fishing industry are the major draws for the tourist industry,
contamination of the waters could have disastrous effects on local economies.
The associated nutrients, pathogens, and toxicants from the point source discharge of sewage and
septic tank seepage pose a serious threat to coral reef ecosystems, which depend on low-nutrient,
high-clarity water (De Freese, 1991). Coral reefe are stenotropic ecosystems, having very narrow
physiological tolerance ranges for physicochemical parameters (Johannes, 1975; Endean, 1976).
Chronic, low-level water quality degradation may seriously impact sensitive life stages, resulting
in long-term changes in community structure and stability. The structure and function of plant-
herbivore relations, algae-coral competition, and reef fish communities are altered by pollution
stress (Johannes and Betzer, 1975; Brock et al., 1979). Environmental perturbations can be
detrimental to the growth and survival of corals (Johannes and Betzer, 1975; Endean, 1976;
Pearson, 1981) and will eventually affect those organisms that depend on corals for food and
shelter (Johannes, 1975). Also, tropical temperatures increase the solubility, biotic uptake, and
toxicity of potential toxics discharged in the effluent, further compounding the environmental
impact (Johannes and Betzer, 1975).
A cooperative study plan (Southeast Florida Outfalls Experiment, or SEFLOE), which pooled the
resources of Federal, State, and local governmental agencies, was initiated in 1988. This joint
venture was designed to characterize the effluent and determine the toxicity of discharges from
the six publicly-owned treatment works (POTWs) located along the southeast Florida coastline.
Methods never before used to determine plume dynamics were tested in conjunction with
conventional methods. The new methodology was based on the detection of the acoustic
backscatter of sound waves transmitted through the water column. This method had previously
been used to discern areas of high particulate concentrations, but it had never been used to
illustrate effluent plumes. The results of this study had some shortcomings, which fueled the
effort to create a second study that is similar in scope but is expected to provide more
comprehensive and more conclusive data. Both SEFLOE studies are discussed in greater detail
in Section 4.1.
4-1
-------
Section 4.2 describes the treatment process, the results of the bacteriological analyses, and
toxicity testing from the 1988 SEFLOE, the National Pollution Discharge Elimination System
(NPDES) permit requirements, and a summary of the monthly discharge data for the six POTWs
of interest. This section provides a quantitative perspective of the point source discharges located
within the study area.
Sewage pollution impacts on delicate biological communities have been placed into three broad,
interacting categories: nutrient enrichment, sedimentation, and toxicity (Pastorok and Bilyard,
1985). Section 4.3 characterizes the effluent discharged by the six wastewater treatment facilities
and discusses the potential impact those discharges may have on marine environments located
along the southeast coast of Florida.
4.1 Southeast Florida Outfalls Experiments
4.1.1 SEFLOE I
In 1988, the Southeast Florida Outfalls Experiment (SEFLOE) was initiated by a cooperative
agreement between the Miami-Dade Water and Sewer Authority Department, Broward County
Utilities Division, South Central Regional Wastewater Treatment and Disposal Board of Palm
Beach County, City of Hollywood Utilities Department, City of Boca Raton Public Utilities
Department, Florida Department of Environmental Regulation (FDER), and National Oceanic and
Atmospheric Administration. The objective was to characterize the physical dispersal conditions
and the environmental impacts caused by the following six POTWs: Delray, Broward County,
Boca Raton, Hollywood, Miami-Dade North District, and Miami-Dade Central District.
The SEFLOE project had four principal objectives:
• To characterize the oceanographic conditions associated with the southeast Florida
coast that encompasses the six outfalls;
• To define and characterize the zone of initial dilution (ZID), as well as the farfield
plume boundaries;
• To determine the toxicity of the whole effluent and of the diluted effluent found
within the mixing zone, which would be done with and without chlorination; and
• To determine the natural capability of open ocean water to disinfect effluents treated
to secondary treatment levels.
Two-day surveys were conducted between October 1987 and June 1988 for each of the six
outfalls. On the first day of sampling, all treatment and chlorination activities proceeded as
usual; on the second day of sampling, however, chlorination ceased and Rhodamine-WT dye was
injected into the effluent prior to its entrance into the discharge pipe. The 2 days of sampling
per facility were not necessarily conducted on consecutive days. Plume dispersion and mixing
4-2
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characteristics were examined using Rhodamine-WT dye tracer studies and acoustic backscatter
techniques. Acoustic backscatter equipment had been previously employed for high-particulate
wastewater projects, but had never been used to determine effluent dilution in ocean waters.
Prior to its use in the SEFLOE project, the equipment was calibrated and the results validated
against traditional methods of measuring plume dilution. The plume was acoustically scanned,
and the results were used to create characteristic dilution curves that describe the spatial and
temporal characteristics of plume dispersion.
Open ocean outfalls have two primary mixing zones. The zone of initial dilution (ZED) occurs
where the freshwater effluent rises towards the surface, forming a surface plume or boil. From
this point, the effluent flows horizontally with the prevailing current, forming the farfield mixing
zone. The initial dilution is used to determine appropriate effluent concentrations for acute
toxicity testing, and the farfield dilutions are used to determine chronic toxicity testing
concentrations and compliance with Class HI water quality criteria (e.g., the criterion for fecal
coliform bacteria is 800 counts/100 mL with a geometric mean of 200 counts/100 mL at the edge
of the mixing zone). A Class III surface water is classified according to the State of Florida
water quality criteria as designated for use in recreation, propagation, and maintenance of a
healthy, well-balanced population of fish and wildlife. The largest amount of mixing occurs in
the ZID. The minimum dilution values (same as the initial dilution values) for the six outfalls
ranged from 36:1 to 71:1 (seawateneffluent). Dilution curves were developed from data obtained
from the farfield mixing zone.
All six farfield mixing zones conformed to the 4/3 rule (Brooks, 1960; USEPA, 1982), a method
developed for predicting farfield dilution in open coastal waters. The method states that the
lateral diffusion coefficient increases as the 4/3 power of the wastefield width. The equation is
as follows (USEPA, 1982):
where
e = lateral diffusion coefficient, ft /sec;
e0 = diffusion coefficient when L = b;
L = width of sewage field at any distance from the ZID, ft; and
b = initial width of sewage field, ft.
The initial diffusion coefficient is determined by
eo = 0.0001 fc4/3
4-3
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The centerline dilution, Ds, can now be calculated by
D. =
erf
1.5
\l/2
-1
1 +
«_yY
b2 J
-1
where
t = travel time, hr, and
erf = the error function.
The use of this mathematical procedure for determining dilutions can be time-consuming. Table
4-17 in Revised Section 301(h) Technical Support Document (USEPA, 1982) lists the dilutions
that correlate to various initial field widths (10 to 5000 ft) and travel times (0.5 to 96 hr). This
table is not always applicable for outfalls located in shallow waters and plumes with long travel
times. In those instances, EPA recommends that the subsequent dilution be determined using a
constant lateral diffusion coefficient rather than the 4/3 law (USEPA, 1982).
A worst-case plume configuration was developed to correlate the plume area with the
downcurrent distance from the ZID. This resulted in an isosceles triangle composed of the angles
20 degrees (vortex), 80 degrees, and 80 degrees. The vortex was located over the outfall, and the
triangle was oriented in the direction of the current. The area of the plume (Figure 4-1) for any
given range, r, can be calculated using the equation
A = r2 tan 0/2
where r is the range and 0 is the vortex angle. In this instance, © = 20 degrees. Florida
Administrative Code (FAC) 17-4 allows a maximum mixing zone of 502,655 m2 and requires that
a minimum dilution of 500:1 be achieved within that mixing zone. Using the above triangle
dimensions, this allows a plume to extend 1,700 m from the outfall. The dilution curves from
the six facilities were used to determine whether the respective effluents achieved the minimum
dilution of 500:1 within this distance.
The data from the SEFLOE I study consisted of three principal components: in-plant
measurements, at-sea field measurements, and laboratory analyses.
In-Plant Measurements
Rhodamine-WT dye was injected into the effluent upstream of the outfall pipe at the rate required
to maintain an effluent dye concentration of 1 part per million (ppm). On each day of the study,
water samples were collected every 30 minutes at a location between the injection point and the
outfall and analyzed for dye concentration, fecal coliform, fecal streptococcus, total coliform,
chlorides, and suspended solids.
4-4
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TOTAL PLUME AREA-A r ' A 2
Figure 4-1. Typical surficial plume configuration and triangle sector approximation (Proni
and Damman, 1989).
At-Sea Field Measurements
The at-sea field operations collected acoustic backscatter data along transects while the research
vessel was under way, and water samples were collected while the vessel was on-station. Vessel
location was maintained using a Loran C with an accuracy of ±15 m. Mean surface currents
were measured using a drifting spar buoy with a drogue placed in the water for a period of time
consistent with the collection of the acoustic backscatter data. (See Table 4-1.) The distance
between the drop-off point and the retrieval point was calculated by the Loran C and divided by
the drift time. An electromagnetic current meter was moored to the outfall at a mid-water
position and programmed to record the vector at 30-second intervals. Temperature and
conductivity profiles (as a function of depth) were also recorded at the outfall. The T-C profiles
collected during the fall and winter months did not indicate vertical stratification; however, the
summer T-C profiles from the Hollywood and Miami-Dade North District outfalls showed some
minor stratification. Vertical stratification tends to sheer the plume and aid the mixing process.
4-5
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Table 4-1. Surface Current Velocities and Direction for the six POTWs
in the SEFLOE I Study
Facility
Sampling Dates
Direction (degrees)
Velocity
(knots)
Delray Beach
01/13/88
165
0.25
Boca Raton
10/07/87
110
0.19
01/12/88
130
. 0.16
Broward County
10/08/87
30
0.66
01/11/88
135
0.22
Hollywood
06/06/89
358
0.87
06/07/89
348
0.24
Miami-Dade North
10/18/87
92
0.32
10/20/87
80
0.34
06/10/88
0
1.0
Miami-Dade Central
10/27/87
19
0.24
01/24/8
335
1.1
The seawater samples were gathered at 1-m, 7-m, and 15-m depth intervals using a 10-L Niskin
bottle. Subsamples were used for biotoxicity testing, water quality, and dye concentration
analyses. Microbiology samples were taken at 1-m intervals using sterile bottles.
Acoustic backscatter (high-frequency echo sounding) was the primary tool used to determine the
spatial variability and distribution of the effluent plume. The transducer was towed across the
plume, sending a sound pulse vertically downward every 0.24 second. The pulse, which
traveled at 1,500 meters per second, was scattered back to the surface by discontinuities in the
water column. (The discontinuities, which consist of differences in particulate concentrations,
alter the intensity of the scatter, thereby providing a measure of the concentration.) By towing
the transducer across the plume, a profile of the particulate concentration, as a function of depth
and position, was created. This image represented a cross-sectional view of the particulate
scattering field along the vessel's heading.
Laboratory and Sample Analysis
In-plant and at-sea samples were subdivided for the analyses. The analyses consisted of tests
for dye concentration; bacteriological analyses; and suspended solids, chlorides, and toxicity
testing. The bacteriological samples were further divided into fecal coliform, fecal streptococ-
cus, and total coliform.
4-6
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organism (USEPA, 1991). Acute toxicity tests determine the LC^ for the effluent. The LQo is
defined as the concentration of effluent required to induce 50 percent mortality of the test
organisms within the designated time period. Chronic toxicity tests measure the no-observed-
effect concentration (NOEC), which indicates the effects of an effluent on larval growth,
reproduction (fertilization and fecundity), and embryo/larval survival (USEPA, 1991). The
NOEC is defined as the highest tested concentration of an effluent at which no adverse effects
are observed on the test organisms at a specific time of observation (USEPA, 1991).
Screening toxicity tests were performed on water samples collected from the treatment plant prior
to discharge, from within the ZID, and from the farfield mixing zone. Definitive toxicity tests
were conducted using plant effluent at test concentrations of 1, 10, 30, 60, and 100 percent. LCjo
values for each of the facilities were determined from the definitive tests. All tests used the
acute 96-hr methodology using the sheepshead minnow, Cyprinodon variegatus, and the mysid
shrimp, Mysidopsis bahia, as test organisms.
Data Analysis
The primary product of the SEFLOE project was a characteristic dilution curve for each of the
six outfalls (Figure 4-2). The characteristic dilution curve can be determined using one or a
combination of the existing subfields, Fh of the wastewater plume field, FF. This curve can be
used to determine effluent dilution and compliance with Class III water quality criteria.
Initial dilution is the process undergone by the effluent as it travels through the discharge pipe
and the water column to the zone where it makes its nearest approach to the surface. This zone,
which may be near or at the ocean surface, is commonly referred to as the boil. For all six
outfalls examined in the SEFLOE project, the effluent plume was confined to the upper 8 m of
the water column.
As previously mentioned, the wastewater plume field, FF (r, 0, z, t), is composed of several
subfields, F, (r, 0, z, t), where FF = F„ ... Fd ... F„. These subfields, which may include the
fecal coliform field, fecal streptococcus field, temperature field, kinetic energy field, acoustic
backscatter strength field, total coliform field, and dye tracer field, can be used to calculate the
initial dilution. The initial dilution for any particular field is expressed as the ratio of the
concentration measured in the boil to the effluent insertion concentration. The equation is as
follows:
F, (r, 0, z, t) Boil
Initial Dilution =
F{ (t-At) Effluent
where At is the time required for a unit of effluent to go from the in-plant measurement site to
the boil measurement site. This is commonly referred to as the detention time.
4-7
-------
1.0
0.1
0.01
0.001
o Brow
d Boca
o Miarr
x Holly
* Miarr
• Delrc
3rd (0.0:
Raton (
i-Centra
vood (0.
i-North
y (0.003
Initial]
0.023 In"
(0.018
315 Initic
(0.014 Ir
Initial)
tial)
Initial)
i) „
itial)
1 1 1 1 1 1 1 1
-
-
- •
is
-
0 150 300 450 600 750 900 1050 1200 1350 1500
Distance from Outfall (meters)
Figure 4-2. Characteristic dilution curve for South Florida outfalls.
-------
Once the effluent reaches the farfield zone, the dilution dynamics are determined by
oceanographic processes rather than by effluent plume characteristics. As mentioned above, a
single sub field or a combination of subfields may be used to derive the characteristic dilution
curve (CDC). The concentration ratio, 6(r), of the CDC at any given range, r, is calculated by:
(FA (FJr))
5(r) = 1-^-x D
for the dye (D) subfield where b = boil and e = effluent. The validity of the acoustic data can
be tested by calculating the 6(r) for the acoustic scatter subfield and comparing it with the 6(r)
for the dye subfield. Once developed, the characteristic dilution curve can be used to calculate
the concentrations of parameters, such as fecal coliform, at the edge of the mixing zone. Of
course, in the case of fecal coliform, this value would be the result of physical dilution only and
would not indicate any deviation due to die-off. The characteristic dilution values for the six
POTWs used in the SEFLOE I study are listed in Table 4-2.
The characteristic dilution curve serves two useful purposes: (1) it determines the dilution
concentrations applicable to chronic toxicity testing, and (2) it determines compliance with State
water quality standards. These values are also useful for determining the exposure of an
organism to an oceanic wastewater plume.
Unfortunately, the data collected from the monitoring program were insufficient to conclude that
"no unreasonable degradation" was occurring in the marine environment off southeast Florida.
The sampling period of only 2 days did not provide enough data points, and the total suspended
solids and the acoustic backscatter data did not correlate. The plume dynamics, particularly
Table 4-2. Characteristic Dilution Values with Range for the Six POTWs
in the SEFLOE I Study
Range
(meters)
Delray
Beach
Boca Raton
Broward
County
Hollywood
Miami-Dade
North
Miami-Dade
Central
0
333:1*
43:1
36:1
67:1
71:1
56:1
100
NA
53:1
45:1
87:1
87:1
85:1
200
NA
73:1
56:1
116:1
119:1
128:1
300
NA
100:1
71:1
185:1
165:1
164:1
400
NA
141:1
91:1
270:1
227:1
208:1
500
NA
182:1
111:1
385:1
308:1
263:1
* - Values were determined during extremely rough weather and are not considered to be valid.
NA - Not Available
4-9
-------
subsurface effluent entrainment and dilution patterns, proved to be far more complex than was
originally believed. The main concern was that plume dynamics were not fully identified from
the study and possibly pockets of undiluted water were leading to the increased algal growth
along the shoreline or were transporting high concentrations of fecal coliform bacteria. These
uncertainties led EPA Region IV to require more intensive monitoring of the POTWs' effluents.
4.1.2 SEFLOE II
Currently, the National Oceanic and Atmospheric Administration (NOAA), in cooperation with
the wastewater treatment facilities, the U.S. Environmental Protection Agency (EPA), and the
Florida Department of Environmental Resources, is conducting a follow-up investigation known
as SEFLOE II. The objective of SEFLOE II is to provide a comprehensive and more conclusive
database related to plume dynamics and the impact of the POTWs' effluents on the marine
environment. Small boat operations will collect twice-monthly water samples for a period of
1 year. The water samples are to be analyzed for microbial (fecal coliform, total coliform, and
enterococcus), nutrient (TKN, nitrates, nitrites, ammonia, and total phosphorus), and oil and
grease content. More intensive shipborne operations will be conducted two times during the year
for water sampling, dye studies, acoustic data collection, and temperature and conductivity
profiles. Current, temperature, and conductivity measurements will also be collected continuously
for a year from instruments moored to the bottom.
4.2 Facility Description and Effluent Characterization
This section describes the wastewater treatment facilities and the location and design of the
outfalls of the six POTWs examined in the SEFLOE I study. Following these descriptions are
the results from the bacteriological analyses and the toxicity testing from the SEFLOE I study.
These results were not available for the Delray Beach facility.
4.2.1 Delray Beach
The municipal wastewater treatment facility located in Delray Beach has a design capacity of
24 MGD. The discharge pipe has a diameter of 46.2 cm, extends 1,609 m into the Atlantic
Ocean, and terminates at a depth of 29.2 m. Treatment processes consist of coarse screening,
grit removal, activated sludge biological treatment, secondary clarification, and chlorination. The
sludge is thickened by air flotation or centrifuge and then lime-stabilized. The final sludge is
disposed of by means of land spreading.
4.2.2 City of Boca Raton
The wastewater treatment facility for the City of Boca Raton has a design capacity of 20 MGD
and an open ocean outfall. Treated wastewater is discharged into the Atlantic Ocean 1,524 m
from the shoreline at a depth of 27.4 m. The discharge pipe undergoes two expansions along its
4-10
-------
length, starting with a diameter of 76.2 cm, expanding to 91.4 cm, and expanding again to
106.7 cm.
The raw influent is treated by the screening of solids, grit separation, primary clarification,
conventional stabilized activated sludge in three aeration basins, and secondary clarification. The
sludge is anaerobically digested, dewatered to 12 percent, and disposed of in a landfill.
4.2.3 Broward County North District
The Broward County North District wastewater treatment facility, located in Pompano Beach, has
a design capacity of 66 MGD. The treatment processes consist of screening and grit removal,
activated sludge biological treatment, secondary clarification, and chlorination. Treated
wastewater travels through a 137-cm-diameter pipe prior to its discharge into the Atlantic Ocean.
The terminal end of the pipe is 2,134 m from the shoreline and at a depth of 33.5 m. Sludge is
thickened by flotation before being anaerobically digested and filter pressed. The final sludge
is disposed of in a sanitary landfill.
Bacteriological Data
Bacterial counts (colonies/100 mL) during chlorination (October 8, 1987) were consistently low
and ranged from 0 to 10 for total coliform, from 0 to 10 for fecal coliform, and from 0 to 150
for fecal streptococcus. The bacterial counts from January 11, 1988, when there was no
chlorination, are reported as being inconsistent. Within the zone of initial dilution (ZID) they
ranged from <100 to 4500 for total coliform, <10 to 530 for fecal coliform, and 40 to 260 for
fecal streptococcus. Ranges recorded within the farfield mixing zone were <100 to 1100 for total
coliform, <10 to 240 for fecal coliform, and 30 to 490 for fecal streptococcus.
Bioassay Data
Acute toxicity screening tests were conducted on 43 water samples taken from the ZID and the
farfield mixing zone. The sheepshead minnow, Cyprinodon variegatus, was used in 24 of the
tests and the mysid shrimp, Mysidopsis bahia, was used in 19 of the tests. None of the water
samples proved to be toxic to either organism.
Definitive acute toxicity tests were performed using effluent dilutions of 6, 12, 25, 50, and 100
percent. Twelve tests used the sheepshead minnow and resulted in LC50 values (the effluent
concentration that is toxic to 50 percent of the test organisms) of 100+ percent. The mysid
shrimp was used for eight tests, and the resulting LC50 values were 100+, 100, and 85 percent.
Presently, the State requires that effluent be nontoxic at a concentration of 30 percent. The LCS0
values obtained from the definitive tests indicate that the Broward County effluent is well within
the FDER requirement.
4-11
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4.2.4 City of Hollywood
The Hollywood municipal wastewater treatment facility discharges primarily residential
wastewater at a rate of 38 MGD into the Atlantic Ocean. The outfall pipe has a 152.4 cm
diameter and extends 3,048 m offshore, terminating at a depth of 27.4 m. The facility's
treatment processes consist of screening and grit removal, two parallel pure oxygen activated
sludge reactors, six secondary clarifiers, and postchlorination. The sludge is thickened by gravity
beds and stabilized with lime. The resulting dewatered sludge is disposed of via land application
in nearby agricultural areas.
Bacteriological Data
Water samples were collected at the treatment plant, within the ZID, and in the farfield mixing
zone, with and without chlorination. The samples were tested for total coliform, fecal coliform,
and fecal streptococcus. During chlorination, bacteria levels (colonies/100 mL) within the mixing
zone ranged from 0 to 48 for total coliform, 0 to 18 for fecal coliform, and 0 to 95 for fecal
streptococcus. Bacterial data for the unchlorinated samples were incomplete and were not
included in the final report. The report noted that fecal coliform samples collected at 800 m
from the outfall were either at or above acceptable levels, whereas samples collected 400 m from
the outfall were at completely acceptable levels. Laboratory error was speculated to be
responsible for the confounding results.
Bioassav Results
Fifteen 96-hr acute toxicity tests were performed using samples of effluent that were collected
prior to dilution at the end of the pipe. The mortality of the invertebrates (Ceriodaphnia dubia,
Daphnia pulex, and Mysidopsis bahia) was 100 percent, and the survival of the vertebrates
(Pimephales promelas and Cyprinodon variegatus) was 100 percent. Previous water samples
have contained the organophosphate pesticide Diazinon, and toxicity tests proved Diazinon to be
the source of the invertebrate mortality. Seventy-two toxicity tests were performed on water
samples collected within the ZID and the farfield mixing zone. None of the samples proved to
be toxic to the test organisms.
4.2.5 Miami-Dade North District
The Miami-Dade North District municipal wastewater treatment plant has a design capacity of
80 MGD and a discharge outfall located in the Atlantic Ocean. The discharge pipe extends
3,353 m offshore, has a 228.6-cm diameter, and terminates at a depth of 32.9 m. The T-shaped
diffuser (Figure 4-3) comprises twelve 61-cm ports (six on each side of the T) and has a total
length of 112.5 m. Treatment at this facility consists of prescreening, primary settling, degritting,
activated sludge, secondary clarification, and disinfection. The sludge is pumped to the Miami-
Dade Central District facility, where it is anaerobically digested, air dried, and used as fertilizer.
4-12
-------
23* 33'09" N
'80* II' 1 a" W
88° 00'00" Azimuth (from chart)
25" 53'13" N
80° 05' 10 "w
Inv. E!ev.-I075
1,000 Long-90 Oia. Cone. Pipe
MSL Shoreline
369'Long 60" Dia. Cone. Pipe
l2-24"Ports of Ports-El8v.-95
40 40 | 40 1 40
41" . 4Q'. 4Q' . 40' 40'.
2-Opposed Openings-^
O-JL—JL
J B 1^1 IL
2-Opposed Openings
180
tszt
-*4-
180
Figure 4-3. Schematic of the Miami-Dade North District discharge pipe and diffuser.
Bacteriological Data
During chlorination, total coliform counts ranged from 0 to 10 per 100 mL, fecal coliform ranged
from 0 to 10 per 100 mL, and fecal streptococcus ranged from 0 to 45 per 100 mL. These
values fall well within the requirements established by the FDER. Data from the 2 days when
chlorination did not occur are inconsistent and do not correlate with previous sampling efforts.
Bioassav Data
Screening toxicity tests were performed on water samples collected from the treatment plant prior
to discharge, from within the ZID (29 samples), and from the farfield mixing zone (26 samples).
Definitive toxicity tests were conducted using plant effluent at test concentrations of 1, 10, 30,
60, and 100 percent. Both types of tests (screening and definitive) were acute 96-hr toxicity tests
using the sheepshead minnow, Cyprinodon variegatus, and the mysid shrimp, Mysidopsis bahia.
The 100 percent effluent used in the screening tests proved to be nontoxic to the sheepshead
minnow; however, four of the eight samples tested with mysids proved to be acutely toxic. None
4-13
-------
of the samples from within the ZID were acutely toxic to either organism, and only one sample
from the farfield mixing zone was toxic. This sample caused 60 percent mortality to mysid
shrimp, and its toxicity was thought to be due to the unusually high salinity of the test solution.
The LC50 values from all of the definitive toxicity tests using the sheepshead minnows were 100+
percent. The four tests using the mysid shrimp resulted in LCS0 values of 100+, 100, 63, and 77
percent. All of these results are well above the 30 percent limit imposed by the State.
An EPA-approved pretreatment program was implemented for all the industrial facilities that
discharge to the Miami-Dade North District treatment plant. Pretreatment programs require
industrial dischargers to treat their wastewater prior to discharging it to the POTW. The
pretreated wastewater is subject to compliance with EPA-approved pretreatment standards. Once
properly treated, the industrial wastewater can be discharged to the POTW. Table 4-3 is a
summarization of the results for the Miami-Dade North District treatment facility following the
implementation of the pretreatment program.
4.2.6 Miami-Dade Central District
The Miami-Dade Central District municipal treatment facility discharges primarily residential
wastewater at a rate of 133 MGD into the Atlantic Ocean. The discharge pipe is 5,740 m long
and has two sections. The first section has a 228.6-cm diameter and extends 1,347 m. It is
coupled to a 304.8-cm diameter pipe that extends another 4,393 m (Figure 4-4). The terminal
end has five 122-cm ports and is located in 33.5 m of water. Wastewater from the Central
District is proportioned to two treatment plants located on Virginia Key. Treatment capabilities
at Plant #1 consist of an aerated channel for grit removal, high-rate activated sludge treatment,
and digestion of the sludge upon removal from the final clarification tanks. The facilities at Plant
#2 are similar; however, pure oxygen is used for the activated sludge process. Digested sludge
is dewatered by centrifugation and drying beds. Processed sludge is used for fertilizer by the
nearby agricultural community.
Until the late 1970s, the Miami-Dade Central District outfall extended only 1,347 m from shore.
D'Amato and Lee (1977) developed a kinematic model that illustrated plume behavior for the
Miami-Dade Central District facility. The outfall was located in waters only 5 m deep and
dominated by prevailing winds. The model indicated that the effluent plume entered Biscayne
Bay through Government Cut, Norris Cut, or Bear Cut, depending on wind direction. The
effluent was rarely, if ever, carried offshore. In 1978, plans were developed to add an additional
4,393 m of pipe, creating a discharge pipe that extended 5,740 m offshore and terminated at a
depth of 33.5 m. The relocation of the outfall was one step toward decreasing the impact of
wastewater on areas designated for uses involving human contact.
Bacteriological Data
The October 27 (chlorination day) samples from the farfield mixing zone ranged from 1 to 4
counts per 100 mL for total coliform. Fecal coliform values were undetected, and fecal
4-14
-------
Table 4-3. Summary of Priority Pollutants Detected After Implementation of an EPA-Approved Pretreatment
Program at the Miami-Dade North District POTW
Detected
DER Effluent
EPA
Inorganic Priority
Maximum
Marine Acute
Pollutants
Concentration
Toxicity
(mg/L)
2/86
2/87
2/88
(EMC)
(MAC)
Lead
O.048
ND
0.025
0.500
N/A
Nickel
0.050
ND
0.030
1.000
N/A
Total Cyanide
ND
0.005
0.01 **
NE
N/A
Thallium
0.014
ND
0.00006
0.480
N/A
Antimony
ND
ND
0.027
NE
N/A
Cadmium
ND
ND
0.0039
0.1
N/A
Detected Organic
Priority Pollutants
(ngfl-)
Chloroform*
16
17
13
1,570
N/A
Tetrachloroethane 1,1,1-
27
5.9
ND
1,000
9,020
Trichloroethane
4.1
7.6
8.2
NE
31,200
Trichlorethene
1
1.4
ND
8,000
N/A
Bis (2-ethylhexyl)
13
ND
ND
NE
2,944
Phthalate
Tetrachloroethene
ND
ND
5.1
885
N/A
Phenols
ND
ND
.0034
NE
N/A
* Chlorination by-product
** Test detection limit
ND - Not Detected
NA - Not available
NE - Not established
-------
Pass Structure
-Point C
25° 44'42.2" N
80*08' 35.9" W
25* 44 31.6 N
80° 05' 10.8" W
nv. El#v. - 110
^50
93°30'00" Azimuth
Cnn Elev.-31.3
S 86" 30'00"E
S 86* 30'00" E .*T— 7—
f'T'" 7^T 50 /
!l ^-A4?o' Larva f 25° 44 39.5 N L\a *\i
4420" Loaq LI4,4I3' Lanq- 120" Dia. R.C.P.
90"010. RCR07 47.6W
I
MSL Shoralint
32' , 32" . 32' , 32' IP'
£&' '^-88* '^-9Qf ^-925^-95^-98'
3-43"Circular Ports
Figure 4-4. Schematic of the Miami-Dade Central District discharge pipe and diffuser.
streptococcus ranged from 1 to 37 counts per 100 mL. All values were well below the FDER
limits. The report indicates that the bacteriological data collected on the day of no chlorination
were inconsistent and did not correlate with previous sampling efforts. The data were not
reported, and laboratory and/or sampling error was given as the cause of the inconsistency.
Bioassay Data
Acute 96-hr toxicity tests were conducted on water samples collected from treatment plant
effluent prior to discharge, within the rising plume at the edge of the ZID (16 samples), and in
the farfield mixing zone (24 samples). Both screening (single-dilution) and definitive (multiple-
dilution) tests were performed, using the sheepshead minnow, Cyprinodon variegatus, and the
mysid shrimp, Mysidopsis bahia, as test organisms.
The screening tests using 100 percent effluent proved to be nontoxic to the sheepshead minnow;
however, three of four samples were toxic to the mysids. None of the samples from the ZID or
the farfield mixing zone were acutely toxic.
The definitive toxicity tests used effluent concentrations of 1, 10, 30, 60, and 100 percent to
determine the LCS0 concentration limit. Ten definitive tests were done at the Miami-Dade Central
4-16
-------
District plant—four with sheepshead minnows and six with mysid shrimp. All the tests with the
sheepshead minnows had an LC50 value of 100+ percent, whereas only three of the six mysid
tests had LC50 values of 100+ percent, with the remaining values being 88, 55, and 55 percent.
All tests met the FDER toxicity test requirement of 30 percent.
An EPA-approved pretreatment program was implemented for all the industrial facilities that
discharge to the Miami-Dade Central District treatment plant. Table 4-4 is a summarization of
the results for the Miami-Dade Central District treatment facility following the implementation
of the pretreatment program.
4.2.7 Summary
Yearly average discharge values for each of the six POTWs in the southeast Florida study area
are compiled in Table 4-5. These values were calculated from the monthly data collected from
July 1990 to July 1991 for the NPDES monitoring program.
4.3 Impacts from POTW Discharges
4.3.1 Effluent Plume Dynamics
The characteristics of the terminal end of the discharge pipe (i.e., open-ended or diffuser), the
properties and volume of the effluent, the receiving water, the diffuser design, and the depth of
the discharge pipe determine the possible level of dilution for each of the six POTW effluent
discharges (USEPA, 1982). Perhaps the most significant characteristics are the use of multiport
diffusers and treatment processes that remove large particulates. Properly designed multiport
diffusers can generate sufficient dispersion and dilution to significantly reduce the detrimental
effects of the effluent on the marine environment (Grigg and Dollar, 1990). Nonsaline effluent
rises rapidly upon discharge from the pipe, and as it rises the effluent entrains ambient saline
waters (Figure 4-5). This dilution causes the density to increase and the buoyancy to decrease.
If the water column is stratified, by either a thermocline or pycnocline, the plume will level out
and move horizontally at the point of neutral buoyancy. If the density gradient is insufficient or
nonexistent, the plume will rise to the surface before flowing horizontally with the prevailing
surface current. This completes the process referred to as the "initial dilution." The vertical
distance from the discharge point to the point of neutral buoyancy is known as the "height of
rise" (USEPA, 1982). The volume of water and the underlying seabed are known as the "zone
of initial dilution" or ZID. It is within the ZID that compliance with acute water quality
standards and acute toxicity requirements must be maintained. The benthos underlying the ZID
may be subjected to chronic levels of pollutants, although typically chronic toxicity is measured
in the farfield mixing zone and not in the ZID. Figure 4-6 shows ZID configurations for various
types of diffusers.
4-17
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Table 4-4. Summary of Priority Pollutants Detected After Implementation of an EPA-Approved
Pretreatment Program at the Miami-Dade Central District POTW
Detected
DER Effluent
EPA Marine
Inorganic Priority
Maximum
Acute
Pollutants
Concentration
Toxicity
(mg/L)
2/86
2/87
2/88
(EMC)
(MAC)
Lead
0.064
ND
ND
0.500
N/A
Nickel
ND
ND
0.011
1.000
N/A
Total Cyanide
ND
0.005
ND
NE
N/A
Thallium
0.027
ND
0.00015
0.480
N/A
Antimony
ND
ND
0.025
NE
N/A
Detected Organic
Priority Pollutants
(ktg/L)
Chloroform*
7.1
5.6
7.4
1,570
N/A
Tetrachloroethane
27
5.9
ND
1,000
9,020
1,1,1 -T richloroethane
ND
1.0
4.4
NE
31,200
Trichlorethene
2.2
3.2
2.0
8,000
N/A
Methylene Chloride
ND
ND
24
NE
2,944
Tetrachloroethane
ND
8.5
4.5
885
N/A
Phenols
ND
ND
.0031
NE
N/A
T rans-1,2-Dichloroethene
4.7
1.7
2.0
NE
* Chlorination by-product.
ND - Not detected
NA - Not available
NE - Not established
-------
Table 4-5. Yearly Average Effluent Concentrations for Each POTW of Concern
Flow
BOD
(mg/L)
BOD
(lh/d)
TSS
(mg/L)
TSS
(lb/d)
Fecal Coliform
(counts/
100 mL)
Total
Residual
Chlorine
(mg/L)
Delray Beach
14.5
10.0
1196.6
11.5
1416.8
100.4
2.4
Broward
County
62.4
12.0
6200.7
6.6
3446.8
4.5
N/A
Boca Raton
11.8
8.0
N/A
4.7
N/A
2.3
0.9
Hollywood
36.6
10.3
3125.6
17.2
5272
6.9
N/A
Miami-Dade
North
86.6
13.1
9576.5
19.4
14,138
19.2
0.6
Miami-Dade
Central
124.7
16.8
17,576
14.8
12,065
2.2
2.9
4.3.2 Impacts on Water Quality
The level of impact on the receiving water depends on the quantity and composition of the
effluent, the receiving water conditions, and the level of dilution achieved (USEPA, 1982).
Water quality parameters of the most concern are dissolved oxygen (and biochemical oxygen
demand), suspended solids, nutrients (i.e., nitrogenous compounds and phosphates), toxics, and
coliform bacteria. Pathogenic human enteric viruses also were detected in the vicinity of non-
treated as well as secondarily treated, chlorinated sewage effluents off southeast Florida in the
late 1970s (Edmond et al., 1978).
Increased levels of organic matter from sewage effluent and the subsequent oxidation of that
organic matter may depress dissolved oxygen concentrations in areas that are already existing at
the upper threshold of tolerance (Bathen, 1968; Kinsey, 1973; Johannes, 1975). The ambient
dissolved oxygen concentration is most critical at night (Pastorok and Bilyard, 1985). Reef
communities maintain a constant rate of respiration (Kinsey, 1973), and nighttime oxygen
concentrations may fall to near zero. An increase in the biological oxygen demand resulting from
the oxidation of organic matter by bacteria may depress oxygen concentrations below critical
levels, significantly stressing the reef community. Suspended solids impact the environment by
increasing turbidity, thereby lowering the transmission of light through the water column. This,
in turn, affects the biological communities in a number of ways. The accumulation rate of solids
is dependent on effluent discharge rates, the concentration of suspended solids in the effluent,
settling characteristics, current conditions, and the presence of density stratifications (USEPA,
1982). Hydrogen sulfide generation and toxic by-products of pesticides, herbicides, chlorine,
and heavy metals can produce deleterious effects (Grigg and Dollar, 1990), as can increased
4-19
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Figure 4-5. Schematic of wastefield from an open ocean outfall (USEPA, 1982).
nutrient (e.g., nitrates and phosphates) loadings. Simkiss (1969) found that inorganic
orthophosphates, pyrophosphates, and organic phosphates (e.g., glycero-phosphate or adenosine
triphosphate) strongly inhibit the calcification process by acting as crystal poisons.
Effluent from municipal treatment facilities has the potential to adversely impact recreational and
commercial fisheries through the bioaccumulation of toxic organics or the induction of diseases
that lower or eliminate the marketability of the catch (USEPA, 1982). Fish embryos are also
sensitive to sewage effluents, resulting in toxic effects on embryo viability, time of hatching,
mortality during hatching, post-hatch larval survival, and larval feeding (Costello and Gamble,
1992).
4-20
-------
NOTE: d*water depth
Figure 4-6. Types of diffusers and their corresponding ZID configurations (USEPA, 1982).
4-21
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Most Significant Factors Affecting Water Quality
• The Miami-Dade North, the Miami-Dade Central, and the Broward
County facilities discharge the largest quantities of effluent.
• The Miami-Dade North, the Miami-Dade Central, and the Broward
County facilities also discharge the highest concentrations and loadings
of BOD.
• The highest loadings of TSS are from the Miami-Dade North, Miami-
Dade Central, and Hollywood facilities. Although Miami-Dade Central
has a higher loading than the Hollywood facility, the Hollywood plant
has the higher TSS discharge concentration.
• The Delray Beach facility discharges the highest concentration of fecal
coliform despite the fact that it is second only to Miami-Dade Central
for total residual chlorine.
• All six of the POTWs complied with the Florida Department of
Environmental Resources' requirements for toxicity. None of the
effluents proved to be acutely toxic.
4-22
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5. NONPOINT SOURCE CONTRIBUTIONS TO WATER QUALITY
Nonpoint sources of pollution are those that cannot be attributed to one specific source. The
primary contributor to nonpoint source (NPS) pollution in coastal areas is urban runoff. As
discussed later in this section, the nonpoint source loadings associated with urban areas are
usually a function of the land use and land activity.
5.1 General Land Use Patterns
The development of land is a major contributor to nonpoint source pollution, primarily because
of stormwater runoff from both urban and agricultural land uses. As the area is developed, the
amount of impervious area and actively maintained landscape areas increases, leading to
increased runoff and pollutant loadings. Figures 5-1 through 5-3 illustrate the general land use
distribution throughout the counties in the study area. Table 5-1 shows general land uses for
the three counties in the study area.
5.2 Sources of Nonpoint Source Pollution
There are a variety of contributors to the nonpoint source loading of pollution, including urban
stormwater runoff, agricultural runoff, marinas, and mismanagement of household toxics.
5.2.1 Urban Stormwater Runoff
As an area becomes developed, the amount of impervious surface increases, thereby increasing
the volume and velocity of runoff. In addition, the amount of actively maintained landscape
increases as an area is developed. Landscope maintenance may lead to increases in nutrient and
pesticide loadings from excess application. Urban runoff contains a variety of nonpoint source
pollutants, including heavy metals, hydrocarbons, fertilizers, pesticides, and oils and greases,
depending on the land use. Unless stormwater runoff is treated using best management practices
Table 5-1. General Land Uses for Counties in the Study Area (Acres)
County
Urban
Agriculture
Range
Land
Forested
Upland
Wetlands"
Water
Barren
Land
Total
Broward
161,633
44,071
25,093
9,013
502,119
14,956
4,575
781,460
Dads
223,702
93,470
10,774
32,902
872.398
198,078
5,790
1,437,114
Palm Beach
224,423
587,823
6,579
30,209
401,931
168,181
4,047
1,416,157
SOURCE: South Florida Water Management District data, 1991, unpublished.
¦ The majority of these wetlands are within the Water Conservation Areas or Everglades National Park.
5-1
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5-2
-------
See legend on p. 5-9.
10MHES
Source: SFWMD, 1992.
Figure 5-1. General land use for Broward County.
5-3
-------
-------
I0MILES
lource: SFWMD, 1992
Figure 5-3. General land use for Palm Beach County
'
-------
Legend for Figures 5-1 through 5-3.
¦
Urban
¦
Commercial/Industrial
~
Recreation and Open Space
¦
Water
¦
Agriculture
¦
Wetlands
-------
depending on the land use. Unless stormwater runoff is treated using best management practices
(BMPs) prior to discharge to coastal waters or their tributaries, these pollutants may end up
offshore. Estimates of various pollutant loadings from three urban land uses are presented in
Table 5-2.
Table 5-2. Estimated Stormwater Pollutant Loads for South Florida (Ib/ac/yr)
Land Use
TOC
BOD
COD
TN
TP
Pb
TSS
Zn
Highway
0.41
rVa
0.94
0.02
0.002
0.007
14.0
0.002
Commercial
0.40
rVa
1.8
0.02
0.002
0.010
9.9
0.003
Residential
0.42
0.46
0.70
0.046
0.009
0.003
n/a
0.003
SOURCE: Adapted from Wanaliesta and Yousef, 1985.
Pollutant loadings vary depending on several factors, including volume of rainfall, amount of
impervious surface, land use, and effectiveness of best management practices (BMPs) in use.
Practices such as allowing open space and buffer areas to filter stormwater runoff, minimizing
use of pesticides and fertilizers, street sweeping, and public education will minimize the
contributions of urban areas to nonpoint source pollution.
5.2.2 Agricultural Runoff
Agricultural land uses are very chemically intensive. Application of pesticides and fertilizers is
a necessary component. Land tilling and erosion account for large quantities of sediment being
carried away by runoff. Because of the relatively flat topography of the area, erosion from
agricultural areas is not as critical a concern in South Florida as it is in other parts of the country;
however, because of the geology of the area (limestone substrate containing an unconfined
aquifer), pollutants can be introduced directly into the water table and flow to the secondary and
primary canals and ultimately to the coast.
5.2.3 Marinas and Other Nearshore Industries
Commercial marinas are another source of nonpoint pollution. In addition to sewage released
from on-board septic systems, metals and metal-containing compounds have many functions in
boat operations, maintenance, and repair. Copper and tin are found in biocides used to kill
marine fouling organisms that attach themselves to boats and pilings. Lead is used as a fuel
additive and may be released through incomplete combustion and boat bilge discharge. Zinc
anodes are used to deter corrosion of metal hulls and engine parts.
Because they do not dissolve in water and are readily bound to sediment, many of the pollutants
associated with marina activity do not cause problems in the water column but accumulate in the
5-11
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bottom sediments. They become a water quality issue when resuspension of sediment occurs,
as has occurred in the Miami River.
5.2.4 Mismanagement of Household Toxics
Improper management of household hazardous materials and waste can be a significant
contributor to nonpoint source pollution. Sources of nonpoint pollution from households include
improper lawn and garden care, improper disposal of household hazardous wastes (such as
backyard and storm drain dumping), use of phosphate detergents, and failing septic systems. All
of these household activities have the potential to degrade water quality.
Sources of household hazardous waste include household cleaners, automotive products, and lawn
and garden products. These can pose a threat to the environment if disposed of improperly. The
usual undesirable methods of disposal include storm and sanitary sewers, landfilling, illegal
dumping, and long-term storage leading to container deterioration.
It is difficult to determine the volume of hazardous materials that are improperly disposed of and
become nonpoint source pollution. To illustrate the potential impacts of improperly disposing
of household hazardous waste and waste oil, the Washington Department of Ecology estimates
that of the more than 4.5 million gallons of used oil dumped in Washington each year, 2 million
gallons end up in Puget Sound (USEPA, 1988). This is significant given that 1 quart of oil can
contaminate up to 2 million gallons of drinking water. The 4 quarts of oil from a car engine can
form an oil slick approximately 8 acres in size (University of Maryland Cooperative Extension
Service, 1987).
5.3 Runoff Characterization/Estimates of Mass Loadings
As discussed in Section 5.2.1, urban runoff is a major contributor to nonpoint source pollution
in the study area. Because of the extensive drainage system in the area and the porous limestone,
most urban runoff ultimately flows to the canals of the primary drainage system. Best
management practices (BMPs) treat a portion of the urban stormwater runoff; however, much of
the coastal area in south Florida was developed prior to current requirements for treating
stormwater runoff. Therefore, runoff flows untreated from impervious surfaces or maintained
landscapes to surface waters. Agricultural runoff may also have an impact in this area. The
primary system drains from south of Lake Okeechobee, through the Everglades Agricultural Area,
to the more developed portions of Dade, Broward, and Palm Beach counties. In addition, there
is agricultural development, primarily grazing, citrus groves, and ornamental horticulture, in the
eastern portions of the counties.
Table 5-3 provides estimates of loadings for three nonpoint pollutants within the study area.
Flow and water quality data from certain primary canals maintained by the South Florida Water
Management District were evaluated to estimate loadings for certain pollutants. The sites are
identified in Figure 5-4. This information was derived from data collected by the South Florida
5-12
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Table 5-3. Estimated Loadings for Nonpoint Source Pollution
from Select Points in the Study Area
SITE
Flow
(mgd)
BOD
(lb/day)
BOD
(lb/106 gal)
Total P
(lb/day)
Total P
(lb/109 gal)
Total n
(lb/day)
Total N
(lb/108 gal)
1
0.064
0.97
15.2
0.04
0.62
0.8
12.5
2
2,761
30,802
11.2
2,228
0.82
2,383
8.5
3
1,603
2,970
1.9
543
0.34
2,038
1.3
4
924
11,272
12.2
267
0.29
9,907
10.7
5
2,562
28,659
11.2
2,785
1.09
21,020
8.2
6
750
9,211
12.3
749
1.5
6,764
9.0
SOURCE: Adapted from data from the South Florida Water Management District, 1985-1989.
Water Management District, and collection periods and frequencies varied by site. Data were
collected approximately quarterly at each canal site and included flow, BOD, total phosphorus,
and total nitrogen. Other data were collected at some sites, but data collection was not consistent
from site to site. Data in Table 5-3 represent quarterly loadings for canal sites that were
averaged over a 5-year period (1985 to 1989). Missing data were treated accordingly, and times
of zero flow were treated as zero loadings.
Table 5-3 reports pollutant contributions as a loading in pounds per day to indicate an estimate
of the total (or absolute) contribution of a pollutant from the canals. Additionally, data are
presented as a concentration in pounds per million gallons per day to provide a way to compare
estimates of the relative contribution of pollutants.
The data presented here are intended only to illustrate the potential of nonpoint sources of
pollution to affect offshore water quality. The lack of continuous, long-term data collected from
the canals does not allow for cause-and-effect relationships to be evaluated. Additionally, a
linkage of nearshore to offshore pollutant transport has not been established for this study area.
Thus conclusions that nonpoint sources, point sources, or a combination of both causes or
contributes to adverse impacts to offshore communities can not be made from the available data.
The available data are, however, useful for providing an indication of the potential relative and
absolute contributions of point and nonpoint sources of pollution to declines in offshore water
quality and impacts on the coral ecosystems. Trends in the available data are also useful for
targeting pollutant sources and defining cost-effective ways to reduce both point and nonpoint
pollution.
5-13
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Most Significant Factors Affecting NPS Contributions
• The type of land use and the control measures in place to minimize
nonpoint source pollution impacts are important considerations in the
evaluation of the relative contribution of nonpoint source pollution.
• Heavy metals and nutrients are the main constituents of urban nonpoint
source pollution. Their impacts can be controlled through public
education and other nonstructural controls.
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6. CONCEPTUAL MODEL OF ECOSYSTEM AND WATER QUALITY
INTERACTIONS
To better understand the potential impacts of point and nonpoint sources of pollution on southeast
Florida coastal communities and to guide the application of the screening model in the next
section, a conceptual model was developed to provide a graphical representation and descriptive
summary of existing knowledge concerning key ecosystem resources that may be affected by
changes in turbidity, nutrients, and toxics from anthropogenic pollutants found in this area.
6.1 Ecosystem Components and Processes
The key resources included in this assessment are the major coastal aquatic habitats of southeast
Florida. These ecosystems include mangroves (Odum et al. 1982; Odum and Mclvor, 1990),
seagrass beds (Zieman, 1982), and coral communities (Jaap and Hallock, 1990). Although other
types of benthic communities that may be impacted by point and nonpoint source pollution also
occur in this area, such as macroalgal beds, algal turfs, soft-bottom sand, and mud flats (see
Alongi, 1989), they will not be considered specifically here. The mangrove forests and seagrass
beds are primarily confined to estuaries and coastal lagoons.
Coral communities within the study area are poorly developed, but do form an encrusting veneer
over relict reefs that lie offshore (Lighty, 1977; Dodge et al., 1991). The northernmost true coral
reef on the southeast coast of Florida is generally agreed to be Fowey Rocks, approximately 16
km southeast of Miami (Dodge et al., 1991). Coral communities have received the most attention
presumably because of their more sensitive nature, but possibly because of their aesthetic appeal
as a research subject (Hatcher et al., 1989).
The discussion herein of the effects of stress is more extensive for coral communities than for
the other major habitat types as a result of the larger quantity of information available for
synthesis. The conceptual model focuses primarily on the key components of each habitat (i.e.,
coral colonies, mangrove trees, and seagrass plants) while attempting to address impacts to other
components (e.g., sessile invertebrates, epiphytic algae, fish, zooplankton, and phytoplankton)
where information is available. These key components form the primary structural and functional
support for each habitat.
The productivity, biomass, species composition, and areal extent of coral, mangrove, and seagrass
communities are controlled by complex interactions among chemical, physical, and biological
factors, as well as human-induced sources of stress. The issues relating to the effects of point
and nonpoint source pollutants on these habitats are also complex. More than one conceptual
model may need to be developed to adequately address the issues and ecosystems of concern
(USEPA, 1991). For example, an issue-specific model may include:
6-1
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• Perturbation sources - source characterization: the kinds, amounts, locations, and
sources of contaminant entry into the system;
• Affected ecosystem resources - receptor characterization: types, abundance, locations,
and sensitivity of potentially affected valued resources;
• Processes affecting perturbation exposure - exposure assessment: processes affecting
how pollutants get from the source to valued ecosystem resources; e.g.,
bioaccumulation of toxics; nutrient removal due to uptake by micro/macroalgae,
sedimentation, advection, and dispersion; and
• Processes affecting resource stress - toxicity assessment: processes affecting how
pollutants affect valued resources; e.g., light decreases due to increased turbidity or
increased phytoplankton populations reduce benthic macroalgae, seagrass, and coral
growth; toxics may be transformed and transferred through the food chain.
Appropriate issue-specific models of the complex processes occurring in the ecosystem may need
to be subdivided into categories designed to fully understand each of the factors affecting the
habitats and organisms. For example, sewage effluent plume dispersion results in increased
particulate loading (turbidity), increased nutrient availability (eutrophication), and the release of
contaminants that can be taken up by organisms in the water column and sediments
(bioaccumulation). The last process may be subdivided to address contaminant transport
(physical processes), contaminant transformations (chemical processes), and contaminant
bioaccumulation (biological processes). Contaminant transformations could be further subdivided
into those transformations occurring in the water column, biochemical transformations, and
transformations in the sediments (USEPA, 1991).
The conceptual model presented here provides a preliminary look at the sources of ecosystem
stress and the variables that influence the behavior of the ecosystem. These variables include
light, temperature, material inputs, and other influences not under control of the system (Dahl et
al., 1974). Additional subdivisions and modeling of the elements and processes would be
required to provide the information needed for the development of appropriate management
decisions regarding the mitigation of such stresses.
6.2 Status of the Major Ecosystems
The three key habitats of concern have been stressed by recent expansion of the human
population in the South Florida area. It has been estimated that only 23 percent of the mangrove
coverage existing in 1900 still remains in Dade County (Metro Dade County Planning
Department, 1986). Seagrass beds in North Biscayne Bay, north of the Rickenbacker Causeway,
were degraded due to thermal and municipal effluents, dredging and filling operations for
construction of the Intracoastal Waterway, causeway construction, urban runoff, fish processing
and ship construction industry effluents, inland drainage for flood control canals, and opening of
6-2
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two artificial channels between the bay and the ocean (Thorhaug, 1980). Impacts to offshore
coral communities due to human activities remain less certain (Dodge, 1987; Dodge et al., 1991),
although localized impacts due to dredging activity related to beach renourishment projects have
been reported (Marszalek, 1980, 1981). The following subsections present a summary of recent
assessments of stresses and impacts on the coral community off southeast Florida.
6.2.1 Ecological Studies
Goldberg (1973) examined the geomorphology, species composition, and zonation of the three
submarine terraces off southern Palm Beach County (approximately the central portion of the
area). He reported finding 27 species of scleractinian or stony corals, with 15 occuring on the
flat patch reefs on the second reef terrace at a 9-meter depth. The most abundant organisms at
this depth, however, were the octocorals (gorgonians or soft corals), with maximum diversity of
19 species. A total of 39 species of octocorals were found on transects at this site. These
numbers compared favorably with other studies of coral/octocoral fauna in the Caribbean and the
Bahamas. Montastrea cavernosa accounted for nearly 20 percent of all coral colonies, more
common than its congener M. annularis, which usually dominates Caribbean and Florida Keys
reefs. The large polyped M. cavernosa has been found to survive conditions of sedimentation
and turbidity better than smaller polyped species (Lewis, 1960; Loya, 1976). Goldberg (1973)
speculated that this phenomenon was the result of increased turbidity off southeast Florida. He
noted that the terraces were a mile or less from shore "with its associated runoff and canal
effluents" (p. 485), and that several coastal communities were operating sewage outfall pipes that
terminated directly on the outer reef. The elimination or reduction of zooxanthellate (photophilic)
reef corals could be attributed to these factors, Goldberg (1984) stated, since reduced
temperatures and siliceous sand flows that inhibit coral growth farther north did not appear to be
a problem in this study area.
6.2.2 Beach Renourishment Impacts
Several studies have evaluated the impact of activities associated with beach renourishment on
the coral communities of South Florida (Figure 6-1). Unless sand is obtained from an upland
source, beach renourishment most often involves dredging sand from a submerged borrow area
near the renourishment site; therefore, impacts to offshore communities are from two
sources—dredging of fill material and deposition of sand. Three categories of impacts on
organisms result from dredging:
0 Mechanical damage;
° Sediment loading from the dredge plume; and
• Increases in turbidity (Marszalek, 1981).
Mechanical damage occurs when machinery associated with dredging inadvertently comes into
contact with the reef. Such contact can cause permanent or temporary damage, depending on the
6-3
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Figure 6-1. Beach renourishment projects in southeast Florida.
6-4
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extent of the incident. Sources of turbidity can be dredging operations or natural, seasonal
resuspension of sediment as a function of wave climate. Natural resuspension can also be
compounded by the presence of fill on the beach and the quality of the fill (Marzalek, 1981).
The Metro-Dade County Department of Environmental Resources Management conducted a study
from September 18 to November 12, 1980, to correlate coral morbidity and mortality associated
with dredging activities. Dredging ceased on October 19, 1980. The results of the survey
indicate that dredging activities at Miami Beach had affected hard-bottom communities and
resulted in the deposition of a silt layer on portions of the reefs. The most severely impacted
area showed evidence of direct exposure to the dredge turbidity plume. A silt layer was
recognizable over about one mile of reef and then thinned to the north where the reef surface was
patchily exposed. Stony corals appeared to be the most impacted by siltation and turbidity.
Bleaching was observed throughout the survey area, including in 5 to 10 percent of the corals
in the control transects. It was assumed that this finding was also due to natural causes, and not
only the dredging. While it is difficult to distinguish between natural and dredge-induced
bleaching, the bleaching was more severe in areas impacted by silt deposition. The most severe
impacts observed, tissue loss and the presence of silt on the corals, were, in most cases, attributed
to dredging (Marszalek, 1980).
In 1980, the Broward County Environmental Quality Control Board (now the Office of Natural
Resources Protection) surveyed and monitored 12 sites in the vicinity of a beach renourishment
project and its associated borrow area. Fifteen months later, the board resurveyed 10 of the 12
sites in an effort to document changes in the flora and fauna that may have occurred as a result
of conditions related to beach restoration (Goldberg, 1984). Reductions in the coral population
were noted. Scleractinians showed signs of tissue reduction or were missing at three stations.
Reductions of 15 to 50 percent were found at five stations. Two stations showed reduced
gorgonian populations and scleractinian losses. Sponge populations did not appear to vary in any
observed pattern. The locations of the affected stations did not correspond to any geographic
pattern that might be associated with dredging (Goldberg, 1984).
The Broward County Office of Natural Resources Protection monitored another beach
renourishment project from 1989 to 1991. Monitoring occurred prior to, directly after, and one
year after the project at 11 sites (4 in the vicinity of the borrow area, 6 in the vicinity of the
beach fill areas, and 1 reference site). In addition, four core sampling stations (two near the
borrow site and two near the fill area) were established to monitor impacts on infaunal
communities. The macroinvertebrates and macroalgae showed no variations in pattern in
organism diversity and abundance relative to dredge or fill activities at the sites; however, major
faunal shifts were observed in the areas where the cores were taken. This was most likely due
to the altered sedimentary environment. The benthic community in the borrow area was strongly
modified immediately after dredging, and recovery was incomplete 1 year later (Dodge et al.,
1991).
6-5
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The difference in impacts from the 1980 and 1989 beach nourishment projects can be attributed
to several factors. Several permit requirements for dredging were required during the 1989
project that had not been required during the 1980 project. These include the following:
• There is no anchoring or chaining near the reef;
• County staff have access to the site for monitoring at all times; and
• There is a specified buffer area between reef and borrow areas.
In addition, dredgers are using more sophisticated equipment to position dredge machinery to
help avoid impacts to the reefs. Thus, although the hard grounds off the southeast Florida coast
have been altered in recent years due to the physical damage caused by these dredging projects,
future impacts from beach renourishment projects should be minimized.
6.2.3 Fish Community Observations
Shinn and Wicklund (1989) reported on observations made at 16 artificial reef structures off
southeast Florida, including wrecks, abandoned oil rigs, and the Miami-Dade Central District
sewage outfall using a manned submersible. Of all the artificial and natural reefs observed, the
greatest diversity and numbers of fish were at the sewer outfall. Some of the fishes observed
included French grunts (Haemulon flavolineatum), pork fish (Anistostremus virginicus), spade fish
(Chaetodipterus faber), amberjack {Seriola dumerili), horse eye jack (Caranx latus), blue runners
(C. fusus), barracuda (Sphyraena barracuda), Bermuda chubs (Kyphosus sectatrix), yellowtail
(Ocyurus chrysurus), and gray hogfish (Lachnolaimus maximus). Two species, the sting ray
(Dasyatis americana) and the cobia (Rachycentron canadum), were observed at the outfall and
at no other site.
The effluent, with over 90 percent of the solids removed by the treatment plant, had a brown
translucent appearance and did not mix with the water column until it neared the surface. The
fish avoided entering the plume and appeared to be in an excited state, rapidly swimming back
and forth. It was speculated that perhaps the fish were attracted to the sound of the effluent
rushing out of the outfall. The southern area of the outfall is a popular fishing spot; however,
the boil, and the north and west sides of the boil, are avoided. The area is never used by divers.
Effects of other environmental perturbations related to point and nonpoint source pollution have
not been adequately examined in the southeast Florida coastal communities.
6.3 Sources of Stress and Interactions Between Sources
A conceptual model of the sources of stress and their interactions is outlined in Figure 6-2. The
types of stress that affect coral, mangrove, and seagrass communities may be divided into water
quality-related effects and direct physical impacts to these communities. This section will briefly
6-6
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Figure 6-2. Conceptual model of types and sources of stress to coral, mangrove, and seagrass communities.
-------
describe the types of stress and interactions that occur between these stresses. The types of stress
resulting in changes in water quality include sediments, nutrients, toxicants, temperature
variations, oxygen depletion, light reduction, salinity changes, and pathogens. The sources of
these types of stress include point source discharges of treated wastewater from POTWs or other
facilities; nonpoint discharges of stormwater from agricultural, industrial, residential, and urban
areas; discharges from marinas and other nearshore industries; accidental releases of chemicals
(e.g., oil spills); and sediments produced during construction and dredging activities.
As mentioned above, sediment loads in the coastal waters off southeast Florida may increase
through land-clearing activities associated with agriculture and construction, dredging operations,
beach renourishment activities, and the discharge of sediment-rich effluents from industrial and
municipal point sources. Storms and hurricanes are a significant nonhuman source of stress,
producing rainfall, which contributes to nonpoint discharges of sediments. The sediments washed
off during these storms also transport toxicants, oxygen-demanding substances, nutrients, and
pathogens into the marine environment. Increased turbulence due to storms and hurricanes can
also resuspend and transport bottom sediments, which can then be redeposited, resulting in
additional stress. Natural sediment transport along coastlines may also be a source of sediment.
Nutrients are contributed by both point and nonpoint sources, particularly nonpoint pollution from
agricultural watersheds (Dierberg, 1991) and point source pollution from municipal wastewater
treatment plants. Nutrient input (especially that of phosphorus) is closely tied to discharges of
sediments. Hence, storms and hurricanes may have a significant influence on nutrient input.
Approximately 33 percent of the annual total nitrogen and 50 percent of the annual total
phosphorus load to drainage canal waters that discharge to the Indian River Lagoon occurred
during a 6-week period when three major storms occurred (Dierberg, 1991). Sediments from
dredging and construction activity are an additional source of nutrients as a result of the
association of nutrients with sediments. Another, often overlooked source of nutrients is in the
form of nutrient-rich groundwater. Lewis (1985,1987) investigated the contribution of nutrients
from groundwater and concluded that groundwater was the chief source of nutrients for enhanced
coastal production along the west coast of Barbados.
Sources of toxic pollutants also include point and nonpoint sources. Nonpoint pollution includes
pesticides from agricultural activity, metals from mining activities, and pollutants from urban and
residential runoff. Urban and residential runoff can be a source of oils, metals, household wastes,
and pesticides from landscaping activities. Point sources include metals and chemical toxicants
discharged from domestic and industrial sources. An additional source of toxic pollutants to
these coastal communities includes accidental spills of toxic chemicals, particularly oil and fuel.
Coastal communities off southeast Florida may also be affected by changes in water temperature.
Seasonal sources of thermal stress include winter cooling of nearshore surface waters and
upwelling of deep, cooler water from offshore. Air temperatures may fluctuate dramatically on
a seasonal basis, bringing occasional periods of frost during winter and prolonged heat waves in
summer. Warm water stress is generally the result of summer warming of shallow water during
warm, calm periods although larger scale ocean-warming events (e.g., El Nino) may also bring
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unseasonably warm water into the vicinity of these communities. Human-induced temperature
stress is supplied mainly in the form of heated effluents from power and water desalination
plants, but these are not a concern in this study area. Johannes and Betzer (1975) discussed the
effect of changing temperature on the susceptibility of marine communities to stress. Although
a temperature increase can induce an increase in production, respiration increases as well. If
respiration increases more rapidly than production, the P/R ratio will approach 1.0. Thus,
although tropical marine organisms have high rates of production, much of this production is
respired. Therefore, additional stress (e.g., that due to sublethal chemical toxicity) that increases
respiration can easily result in little or no net productivity, leaving little metabolic reserve for
reproduction and maintenance. Higher rates of metabolism, coupled with the generally greater
solubility of pollutants in warmer water, result in rapid uptake of toxicants and hence greater
sensitivity of warm water organisms to pollutants. However, greater uptake rates may be
balanced by equally rapid toxicant elimination rates.
Temperature increase in warm waters also results in lower oxygen concentrations at saturation
levels, placing warm water organisms closer to their oxygen limits (Johannes and Betzer, 1975).
Therefore, slight increases in temperature and minor changes in the amounts of oxygen-
demanding substances discharged to these environments can push oxygen levels to critical levels.
Community respiration may exceed available oxygen reserves at night, resulting in the most
sensitive conditions, especially for coral communities in poorly flushed areas such as lagoons.
Human sources of such oxygen-demanding substances include direct discharges of municipal,
food processing, and paper-making process wastewater. Oxygen-demanding substances from
dredging operations may be an additional source of stress, as well as nonpoint pollution runoff.
Oil spilled in the marine environment also exerts an oxygen demand on the surrounding water
as do a variety of organic chemicals that may be accidentally spilled into coastal areas.
Indirectly, increased eutrophication due to human-caused increases in nutrient loading to coastal
waters may result in periods of oxygen depletion as the result of the bacterial degradation of
phytoplankton biomass following algal blooms. These sources of oxygen-demanding substances
are in addition to the normal respiration (community oxygen consumption) that occurs in these
communities. Oxygen stress is most critical at night due to the absence of oxygen production
by the photosynthetic organisms of these communities.
Photosynthesis is dependent on adequate levels and appropriate wavelengths of light. Light
quality may be altered by the discharge of solids from both point and nonpoint sources of
pollution. Major storms have a significant influence on sediment input to coastal marine systems,
resulting in elevated turbidity and reduction in light intensity. Human activities such as land
clearing, urbanization, coastal construction activities, and dredging all contribute to elevated
suspended sediment levels and turbidity in coastal waters. Eutrophication of coastal waters also
results in increased turbidity and light reduction due to increased phytoplankton biomass.
Stratospheric ozone depletion, on the other hand, may be a source of increased ultraviolet light
intensity. This stress is restricted to shallow, clear water areas under calm conditions, which
allows maximum penetration of light.
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Salinity changes in the coastal area off southeast Florida most likely are influenced by freshwater
runoff (and hence low salinity stress) due to rainfall. The quantity of freshwater runoff
discharged is increased through the removal of vegetation that retains runoff; paving of large
areas, which prevents infiltration of runoff; and the channelization of runoff, which routes
stormwater more quickly to coastal areas. Road construction, channelization, drainage alteration,
and dredging activities can also alter the balance of salinity in nearshore mangrove, seagrass, and
coral communities. Although the effect of storms and hurricanes on runoff is short-lived,
changes in the natural drainage system caused by the storm can cause long-term changes in water
exchange, and hence salinity of these communities. These physical changes may result in
diversion of fresh water (e.g., drainage construction) from these communities and may result in
increased salinity in one location and possibly reduced salinity in the area that receives the
diverted water. Alterations of coastal barriers (channel construction) or channels of tidal
exchange (causeways without adequate culverts) may result in increased or decreased exchange
of seawater, resulting in increased or decreased salinity of the affected areas. Salinity reductions
may also occur in the vicinity of the POTW outfalls. At the Hollywood facility, minimum
salinity values recorded were 27.1 and 24.8 ppt.
Naturally occurring biological factors such as pathogens, parasites, predators, and herbivores are
also important modifiers of species composition, biomass, areal coverage, and productivity of
these coral hard grounds, seagrass beds, and mangroves. While periodic outbreaks of disease and
predation can have widespread and devastating impacts on the structure and function of these
ecosystems, the factors influencing such outbreaks, the reasons why they occur, and how they
interact with complex environmental factors are poorly understood. Some specific examples for
each community type will be discussed further below.
Two additional types of stress that are not directly related to water quality include direct physical
damage and physical alterations of the environment. Physical damage may be human induced
(e.g., direct impact during construction and/or dredging activities), or it may be due to non-human
causes (e.g., tropical storms and hurricanes). Storms and hurricanes have a very significant
impact on these communities directly through physical impacts and indirectly through physical
processes associated with heavy rainfall runoff. The sediments washed off during these storms
transport nonpoint source pollutants such as toxics, oxygen-demanding substances, nutrients, and
pathogens. Finally, changes in the hydric regime (i.e., frequency and extent of exchange of fresh
and/or saline water) of coastal areas due to physical disturbances of the environment are more
subtle. Sources of change in the hydric regime are both human and nonhuman. Human
interference in drainage patterns may cause changes in coastal sediments, nutrients, and salinity.
Storms and hurricanes can produce changes in the original drainage of the mangrove forest,
resulting in either increased or decreased seawater exchange. The effect of these changes will
depend on the input rate of fresh water, evaporation, and the magnitude of the increase or
reduction in the tidal exchange of seawater. Longshore transport of sand may also gradually
enclose mangrove-lined bays and prevent tidal exchange.
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6.4 Potential Effects of Water Quality Alterations on Coastal Communities
This section presents a discussion of the potential impacts of each type of stress on the coral,
seagrass, and mangrove ecosystems along the southeast Florida coast due to the presence of point
and nonpoint sources of pollution. Examples of important processes and effects are also
illustrated graphically. The impacts of sewage pollution can be placed into three broad
categories: nutrient enrichment, sedimentation, and toxicity. Degradation of the marine
environment may result in the following changes in the local biological communities (USEPA,
1982):
• Modification of the structure of benthic communities as a result of the accumulation
of discharged solids on the seabed;
• Stimulation of phytoplankton and/or macroalgal growth due to nutrient enrichment;
• Reduction of phytoplankton and/or macroalgal growth due to turbidity increases;
• Reduction of dissolved oxygen due to phytoplankton blooms and subsequent die-offs,
causing mass mortalities of fish and invertebrates;
• Bioaccumulation of toxic pollutants due to direct contact or ingestion of sediment,
direct uptake from the effluent, or ingestion of contaminated organisms; and
• Induction of diseases from contact with sediments, ingestion of contaminated
organisms, or exposure to the effluent.
Increased levels of organic matter in sewage effluent and the subsequent oxidation of that organic
matter may depress dissolved oxygen concentrations in areas that are already existing at the upper
threshold of tolerance (Bathen, 1968; Kinsey, 1973; Johannes, 1975). The ambient dissolved
oxygen concentration is most critical at night (Pastorok and Bilyard, 1985). Reef communities
maintain a constant rate of respiration (Kinsey, 1973), and nighttime oxygen concentrations may
fall to near zero. An increase in the biological oxygen demand resulting from the oxidation of
organic matter by bacteria may depress oxygen concentrations below critical levels, significantly
stressing the reef community. Hydrogen sulfide generation and toxic by-products of pesticides,
herbicides, chlorine, and heavy metals can produce deleterious effects (Grigg and Dollar, 1990),
as can increased nutrient (e.g., nitrates and phosphates) loadings. Simkiss (1969) found that
inorganic orthophosphates, pyrophosphates, and organic phosphates (e.g., glycerophosphate or
adenosine triphosphate) strongly inhibit the calcification process by acting as crystal poisons.
The impact on the local biota will be indicative of the pollutants to which the biota are exposed,
their concentrations, and the period of exposure.
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6.4.1 Sediments
Excessive amounts of sediments and sedimentation result in the death of reef-forming coral
organisms and degradation of the reef framework. Loss of the reef framework and its associated
structural complexity will result in habitat loss and reduction of coral reef fish (Rogers, 1990).
Heavy sedimentation has been associated with fewer coral species, less live coral, lower coral
growth rates, decreased calcification rates, decreased net productivity, decreased reef accretion
rates, and reduced coral recruitment (Rogers, 1990). Heavy sedimentation will also favor a shift
from the coral benthic community to a benthic community dominated by benthic filter feeders
and detritivores (Banner, 1974; Birkeland, 1977).
Sediments or particulate organic and inorganic matter discharged to coral reef environments may
directly smother corals, result in increased metabolic costs to corals as a result of sediment
removal by the coral organism, reduce the amount of suitable hard substrate on which coral
larvae can settle and attach, or result in abrasion and scour of coral tissue during sediment
resuspension and transport (Figure 6-3). Indirectly, suspended sediments increase turbidity, which
in turn can decrease the amount of light available for coral production associated with their
symbiotic algae (zooxanthellae). Sediments also transport particulate-associated toxic pollutants,
nutrients, oxygen-demanding organic matter, and pathogens. These types of stress will be
discussed further below.
Although it is generally recognized that sedimentation is detrimental to corals, the types and
degree of sedimentation where impairment of coral reef growth, reproduction, and recruitment
occurs have not been determined (Hubbard, 1987). The effects due to sedimentation depend on
a number of factors, which include the type of sediment (grain size distribution, carbonate
content, organic content, toxic pollutant levels); the amount of sediment (i.e., sedimentation rate);
and the duration (e.g., chronic vs. acute effects) and timing of coral exposure (e.g., night vs. day,
reproductive or recruitment period). However, some generalizations regarding the impact of
various sedimentation levels have been made. Rogers (1990) indicated that reefs not subjected
to human-induced stress had average sedimentation rates less than or equal to 10 mg dry-wt/cm2
per day. Tetra Tech (1983) estimated that sedimentation rates of 1 to 10, 10 to 50, and greater
than 50 mg dry-wt/cm2 per day would result in slight to moderate impacts, moderate to severe
impacts, and severe to catastrophic impacts, respectively. Hudson (1981) observed decreased
growth rates of Montastrea annularis colonies in the Key Largo National Marine Sanctuary that
appeared to coincide with the increased dredge and fill operations in the Florida Keys area from
1953 to 1968. Eutrophication along the west coast of Barbados resulted in decreased settlement
rates for coral planulae, thus altering the composition of the reef communities (Tomascik, 1991).
These reduced recruitment rates were speculated to be the result of either increased suspended
particulate matter or toxic effects of the effluents.
Generally, seagrass beds occur in sedimentary environments ranging from clean sand to fine silty
sediments (McRoy, 1983). Additionally, seagrasses act as stabilizers of sediment and may
actually enhance sedimentation within the seagrass bed (Zieman, 1975, 1982). Excessive
sediments, however, can impact the seagrasses through direct sedimentation and smothering,
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nonpoint source
coastal contributions
mangrove
tree areas
I
community
diversity
sediment removal:
advection
dispersion
flocculation
substratum
alteration
point source
contributions
smothering
and
abrasion
phytoplankton
nutrient removal
by sediments
Figure 6-3. Conceptual model of processes and effects relating to sedimentation in southeast Florida coastal communities.
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depletion of oxygen due to oxygen-demanding substances in the sediment, and increased turbidity
resulting in decreased light penetration and subsequent impairment of seagrass photosynthetic
production. Sediments not only affect the seagrasses themselves, but they also influence the
species composition and productivity of the associated seagrass community, which includes
benthic and epiphytic algae, crustaceans, and fish.
Mangroves generally thrive in areas of high sediment loading (e.g., river deltas), but catastrophic
sediment deposition that smothers the mangrove aerial root system can cause tree mortality
(Odum and Johannes, 1975; Cintron and Schaeffer-Novelli, 1983). Mangrove seedlings are also
sensitive (Odum and Johannes, 1975). Fresh deposits of sand associated with sand extraction and
storm waves killed mangroves when the sand deposited was 30 cm deep, and partial mortality
was observed where sediment depth was 20 to 30 cm.
The loss of mangroves due to acute sediment stress would typically be accompanied by losses
of the biotic community associated with the mangrove (e.g., crustaceans, reptiles, amphibians,
and birds). It is also possible that chronic sublethal sediment stress would not cause mangrove
tree mortality, but that biotic communities associated with the mangrove root system would be
affected. On the other hand, increased sediment input, if not catastrophic, could allow for the
gradual expansion of the areal extent of the mangrove forest (Odum and Johannes, 1975).
Sediment diversion should also be considered because of the special requirements of mangrove
forests. Sediments may be diverted from these communities through natural changes in drainage
patterns or through channelization and ditch construction. The prevention of the natural filtration
of stormwater runoff by mangroves allows for increased discharge of sediments to offshore coral
and seagrass communities.
6.4.2 Nutrients
The effect of increased nutrient input to coral reef areas is not well understood, and conflicting
evidence has been presented in the literature. The association of nutrients with increased
sediment input often complicates interpretation of field data. Nutrients may directly affect coral
skeletal growth by inhibiting skeletal calcification (phosphate) (Simkiss, 1964) and may indirectly
affect the coral community through the enhancement of attached algal growth, which may
overgrow living corals or interfere with coral larval recruitment (Birkeland, 1977). Based on
evidence from field studies in the Great BarrieT Reef, Kinsey and Davies (1979) suggested that
phosphate (P04) levels greater than 62 fig VOJL could suppress reef calcification by more than
50 percent. Kinsey and Davies (1979) determined that nitrogen enrichment had no effect on
calcification activity and that calcification may actually be enhanced by elevated levels of
ammonium. However, Stambler et al. (1991) reported no significant differences in the growth rate
of Pocillopora damicornis (collected from Kaneohe Bay, HI) treated with up to 10 times the
ambient phosphate phosphorus levels (61.9 fig PO^/L). Furthermore, Stambler et al. (1991) found
reduced skeletal growth rates due to enrichment with ammonium (210 fig NH4/L) and with
enrichment with ammonium and phosphate together. This reduction in growth was attributed to
a reduction in translocation of zooxanthellae photosynthetic products due to the rapid growth of
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the nitrogen-limited zooxanthellae and/or due to competition with the coral animal for the carbon
dioxide required for calcification.
The more likely effect of nutrient input is the enhancement of benthic algal growth and
subsequent competition with corals for the limited space within the community. Johannes et al.
(1983) suggested that nutrient supply in high-latitude reefs played a significant role (along with
temperature) in controlling coral community structure, explaining the dominance of benthic algae
in these habitat. Littler and Littler (1985) went further to include the role of herbivores in the
control of algal biomass in coral communities. They concluded that nutrient levels determine the
potential size of algal standing stocks, but that herbivores can maintain macroalgal biomass well
below the limits set by nutrient supply. The growth of other suspension feeding and bioeroding
animals stimulated by nutrient inputs, however, may lead to increased erosion of the carbonate
substratum (Rose and Risk, 1985; Hallock and Schlager, 1986). Additionally, nutrient input
could indirectly affect the coral community if a significant fraction of the input is converted to
phytoplankton production. Increased phytoplankton biomass would reduce light levels and shade
coral and seagrass communities, with subsequent detrimental effects (Figure 6-4).
Seagrasses growing with adequate light appear to be nutrient-limited (Williams, 1987, 1990),
although light could become limiting with increased turbidity (Vicente and Rivera, 1982) and/or
with increased water depth (Williams, 1988a). Eutrophication, or the increased rate of input of
nutrients, could enhance the production of phytoplankton and epiphytic algae, which could shade
the seagrasses and cause a decrease in productivity of seagrasses. This could lead to eventual
replacement of the seagrass community with algae (i.e., phytoplankton and/or benthic algae and
periphyton) (Zieman, 1975, 1982).
Generally, the growth and biomass of mangrove forests are considered to be limited by nutrient
input, with the mangrove ecosystem acting as a sink for nutrients, including nitrogen and
phosphorus (Odum and Johannes, 1975; Odum et al., 1982). Therefore, eutrophication of
mangroves has not generally been considered a problem. On the contrary, serious attention has
been focused on using mangrove forests for domestic wastewater treatment (Odum and Johannes,
1975, Clough et al., 1983). Since mangrove productivity and biomass are generally limited by
the nutrient supply, changes in water drainage patterns may have a negative effect on mangroves
when they depend on drainage water for essential nutrients. Nutrient diversion should also be
considered as a stress, particularly in the case of mangrove forests. Nutrient diversion occurs
through sediment diversion techniques, which create drainage systems that prevent the natural
filtration of upland runoff by mangrove forests.
6.4.3 Toxicants
Toxicants, such as chlorine, metals, pesticides, petroleum hydrocarbons, or other organic
pollutants, may directly affect various life stages of corals (gametes, planulae, or larval
settlement) or the various life stages of animals and plants that make up the coral community.
Coral colonies themselves may be fairly resistant to toxic pollutants (Marszalek, 1987), but
certain other coral life stages may be sensitive. Corals exhibit a variety of reproductive
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nonpoint source
coastal contributions
point source
contributions
productivity
oxygen
UAi/MAi/
community
structure
changes:
filter feeders
nutrient removal:
sedimentation
advection
dispersion
biological uptake
demersal i
fish ^
. pelagic y
Figure 6-4. Conceptual model of processes and effects relating to nutrient inputs in southeast Florida coastal communities.
-------
strategies, including spawning of gametes and external fertilization, timing of spawning, and
spawning synchrony among species (Richmond and Hunter, 1990). Therefore, the timing of
pollutant input may play an important role in toxic effects on coral life stages. Although several
toxicity studies have been performed on various life stages of corals, these studies have generally
been performed on tropical Pacific species (Evans, 1977; Acevedo, 1991; Goh, 1991; Te, 1991).
How the toxic pollutants interact with other stressors (e.g., sediments, nutrients, and abnormal
temperature variations) has not been adequately studied.
Coral mortality and coral community alterations due to oil pollution have been noted in several
areas of the Caribbean (e.g., Bak, 1987; Jackson et al., 1989). Loya and Rinkevich (1980)
reviewed research on the effects of petroleum hydrocarbons on corals and concluded that oil
pollution in direct contact with corals can impair coral growth, reproductive systems, and coral
larvae and can cause mortality of corals. Peters et al. (1981) demonstrated that a shallow-water
Caribbean coral, Manicina areolata, could bioaccumulate petroleum hydrocarbons (water-
accommodated No. 2 fuel oil). The highest mean hydrocarbon concentration over the 3-month-
long flow-through test, 150 /zg/L, did not induce coral mortality, but sublethal effects were noted,
primarily impaired development of reproductive tissues, loss of zooxanthellae, and atrophy of
mucous secretory cells and muscle bundles. Te (1991) investigated the effect of two petroleum
products (benzene and an oil and gasoline mixture) on Pocillopora damicornis larvae survival
and settlement. Mortality was minimal in treatments of up to 100 mg/L, but treatments did have
an effect on corallite formation.
McCloskey and Chesher (1971) did not observe any mortality of specimens of Montastrea
annularis, Acropora cervicornis, or Madracis mirabilis to exposure of 10-, 100-, and 1,000-yUg/L
mixtures of p,p'-DDT, dieldrin, and Arochlor 1254, but they did note an increase in respiration
(R) and a decrease in photosynthesis (P) in all three species, which occasionally lowered the P/R
ratio to below 1.0. Exposure of P. damicornis larvae to the pesticides carbaryl and 1-naphthol
of 10 mg/L resulted in greater than 50 percent mortality (Acevedo, 1991). An investigation by
Solbakken et al. (1985) demonstrated that several Bermudian corals could bioaccumulate
naphthalene, phenanthrene, a PCB congener, and octachlorostyrene. Elimination of naphthalene
was rapid, but the PCB congener was depurated very slowly with tissue concentrations of the
contaminant still well above detectable levels up to a year following exposure. Glynn et al.
(1989) detected high levels of organochlorine pesticides and heavy metals in corals and
octocorals collected from Biscayne National Park off southeast Florida, similar to those levels
used in toxicity tests that had led to bleaching and mortality of reef-building corals in the
laboratory (Glynn et al., 1§84).
Evans (1977) exposed the Pacific corals P. damicornis and Montipora verrucosa to solutions of
copper (Cu) sulfate in flow-through systems. Exposures of 100 jug Cu/L resulted in 100 percent
mortality after 24 hours. After 48 hours of exposure to 10 ng Cu/L, corals that had been observed
to be stressed were dead by the sixth day of exposure (Evans, 1977). Exposure of P. damicornis
planula larvae to nickel (9 mg Ni/L) over a 12-hour period caused 50 percent mortality almost
40 hours after discontinuance of exposure (Goh, 1991). Settlement of the larvae was more
sensitive, with effects observed with exposure to 1 mg Ni/L for 12 to 96 hours (Goh, 1991).
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Chlorine is typically used in disinfection of municipal wastewater prior to discharge. Johannes
(1975) reviewed the effect of free residual chlorine on tropical marine organisms. Toxic effects
were observed in marine fish at levels as low as 24 fig/b, while coral planulae of three Hawaiian
corals tolerated exposure to 490 pg/L for up to 7 hours. Marszalek (1987) concluded that corals
were relatively resistant to chlorinated effluents compared to fish, based on tests performed at
an experimental sewage treatment plant in Miami, Florida.
Hydrogen sulfide has also been implicated as a toxicant to corals, partially explaining coral
decline in Kaneohe Bay (Banner, 1974). Hydrogen sulfide production is the result of reduction
of organic matter by bacteria using sulfate as the electron acceptor under anaerobic conditions.
Therefore, hydrogen sulfide production is linked to discharges of oxygen-demanding substances
and oxygen depletion in bottom sediments.
Although some toxicity testing has been performed, these tests have focused on very few coral
species and life stages and have generally exposed the organisms to concentrations greater than
would typically occur in even a heavily polluted environment. Exposure has also generally been
short-term, and the sublethal effects of long-term exposure have been poorly characterized.
Exposure to toxicant-contaminated sediments has also not been considered. These sediments may
be discharged to coral areas by point and nonpoint sources. Through resuspension of
contaminated sediments deposited in coral areas, the coral community may be continually
exposed to sediment toxicants.
The effects of toxicants on seagrass ecosystems, with the exception of oil, have received little
attention (Thorhaug, 1981). Oil damage to seagrasses that has been observed includes extensive
damage to beds on the south shore of Puerto Rico following the discharge of approximately
10,000 tons of crude oil from a grounded vessel. Seagrass mortality and a change of benthic
algal species composition to blue-green algal types was observed over a period of a few months
(Dfaz-Piferrer, 1964). Jackson et al. (1989) reported the mortality of intertidal seagrass beds and
a reduction in biomass and species of animals of the seagrass community due to an extensive oil
spill in the Caribbean along the coast of Panama. However, Jackson et al. (1989) observed that
subtidal seagrasses survived, although sublethal effects such as browning of grass blades and
fouling by epiphytic algae occurred.
Thorhaug (1988) reported on the effects of mixtures of oil with oil dispersants. She concluded
that the toxicity response of seagrasses varied with the dispersant used, but that seagrass species
responded predictably to exposure. Thalassia (turtle grass) was found to be more tolerant than
Halodule (shoal grass), which was more tolerant than Syringodium (manatee grass) (Thorhaug,
1988).
The toxicity of organic compounds and metals to mangroves is dependent on (1) mass loading
of the toxicant, (2) the duration of input, (3) the susceptibility of the organism, and (4) the
physical-chemical factors in the receiving environment, which include temperature, salinity, and
flushing rate (Lugo et al., 1981). Since mangroves occur in a variety of environments (e.g.,
basins, riverine estuaries, and shoreline fringes), their susceptibility to toxicant stress depends
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heavily on the above-mentioned factors. Therefore, basin mangroves may be more susceptible
to inland sources of pollution (e.g., agricultural herbicides), and fringe mangroves may be more
susceptible to seaward sources of pollution (e.g., oil spills) (Cintron et al., 1978; Lugo et al.,
1981).
Mangroves have been noted to be very sensitive to herbicides (Odum and Johannes, 1975; Odum
et al., 1982; Culic, 1984). This conclusion is based on observations of limited mangrove recovery
following large-scale (100,000 ha) defoliation of mangroves with herbicides in Vietnam. Culic
(1984) reported that effects due to soil and foliage applications of 2,4-D applied to Rizophora
stylosa were exhibited at dosages of 0.0125 and 0.3125 kg/ha, respectively. Walsh et al. (1973)
reported that applications of 2,4-D of 4.4 kg/ha were lethal to R. mangle; however, levels of 0.44
kg/ha had no permanent effect.
Oil pollution has caused mangrove mortality throughout the world (reviewed by Lewis, 1983 and
Hoi-Chaw, 1984). The impacts of oil spills on macroinvertebrate populations of the mangrove
have also been noted (Dfaz-Piferrer, 1964; Lewis, 1983; Jackson et al., 1989). Oil dispersants
may also be toxic, and the mixture of dispersed oil may be more harmful than oil alone. While
Hoi-Chaw et al. (1984) showed that dispersed oil was less toxic to mangrove trees and seedlings
than oil alone, the reverse was true for mangrove invertebrates.
Effluent from municipal treatment facilities has the potential to adversely impact recreational and
commercial fisheries through the bioaccumulation of toxic organics (Spies, 1984) or the induction
of diseases that lower or eliminate the marketability of the catch (USEPA, 1982). Young (1964)
produced perhaps the earliest report of the effects of sewer discharges on fishes that were
collected near sewer outfalls on the California coast. He found changes in the consistency of
the flesh, weight reductions, external lesions, exophthalmia (protruding eyes), and papillomas
(tumors). Several other studies have implicated POTW discharges in the proliferation of diseases
such as exophthalmia in spotfin croaker, Roncador stearnsil, and white seabass, Cynoscion
nobilis', lip papilloma in white croakers, Genyonemus lineatus; and fin erosion in fishes of the
New York Bight (Mahoney et al., 1973) and in the Dover sole, Microstomias pacificus (Mearns
and Sherwood, 1974; McDermott-Ehrlich et al., 1977). Marine organisms collected near sewage
outfalls have been known to bioaccumulate chlorinated hydrocarbons and trace metals in their
tissues. These include the Dover sole, Microstomas pacificus; the rock crab, Cancer anthonyi;
the mussel, Mytilus californianus; and the rock scallop, Hinnites multirugosus (Young et al.,
1976, 1978; McDermott et al., 1976; McDermott-Ehrlich et al., 1978).
Fin erosion, ulcerations, papillomas, gill hyperplasia, and lymphocystis are characteristic diseases
of fishes living in degraded habitats (Sindermann, 1990). Large populations of the heterotrophic
bacteria Vibrio, Pseudomonas, and Aeromonas may occur as a result of heavy organic loadings
from domestic sewage or agricultural runoff into estuarine and coastal waters (Sindermann,
1990). These bacteria can produce integumentary or penetrating ulcers on fish that are stressed
from low dissolved oxygen levels, abnormal temperatures, or the presence of other pollutants.
Environmental pollutants may reduce the ability to resist infection. It is believed that mucous
secretion, the principal external defense, is suppressed, leaving the fish vulnerable to bacterial
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infection and fin erosion (Hodgins et al., 1977). In fact, the occurrence of fin erosion has been
correlated to high coliform counts (Mahoney et al., 1973) and high heavy metal concentrations
(Carmody et al., 1973) in sediments. In a study of fishes collected near a municipal sewer outfall
near Los Angeles from 1971 to 1982, the decline in the prevalence of fin erosion was correlated
to a decline in surficial sediment contaminants (Cross, 1985).
Several studies have indicated that the waters of Biscayne Bay are having adverse effects on the
fish populations. These effects include the disruption of normal scale patterns, scale reversals
(Sindermann, 1990), and fibroma-like tumors in the mullet, Mugil cephalus (Sindermann, 1976).
Fishes with severe infestations and gill lesions were taken from the heavily-polluted canal waters
that enter Biscayne Bay (Skinner, 1982). Among the pollutants found in the canal waters
emptying into Biscayne Bay are organic pesticides such as diazinon, silvex, and parathion; heavy
metals such as mercury, lead, and zinc; and ammonia. Figure 6-5 summarizes some of the
processes and effects that need to be considered when coastal ecosystems are exposed to toxic
substances.
6.4.4 Oxygen
Oxygen is necessary for the maintenance of marine life. Low oxygen concentrations or the lack
of oxygen can stress coral communities. During the day, phytoplankton and attached algae
consume carbon dioxide (COj) and produce oxygen (O^ during photosynthesis. Animals
(including corals) consume phytoplankton and other organisms and consume oxygen in order to
oxidize the ingested organic matter and convert it into energy for maintenance, growth, and
reproduction. Aerobic bacteria also consume oxygen in order to decompose the organic matter
shed by the coral community. Thus, during the day the ambient oxygen level of the coral
community is balanced by the production of oxygen through photosynthesis, the consumption of
oxygen by animals and aerobic bacterial degradation, and the input of oxygen through diffusion
from the atmosphere and advection from offshore waters. At night, photosynthetic oxygen
production no longer occurs, due to the lack of sunlight, and respiration (oxygen consumption)
by the coral community can reduce the ambient oxygen concentration if the community is not
well supplied with fresh oxygenated water (e.g., as in a backreef lagoon). Also, because the
respiration rate is typically higher at higher temperatures and the ambient oxygen concentration
is lower at higher temperatures, coral communities in poorly flushed areas may be stressed by
lack of adequate oxygen (Johannes and Betzer, 1975). Therefore, the input of oxygen-demanding
organic matter to poorly flushed coral reefs can have a detrimental effect on coral communities.
Low oxygen levels in seagrass beds can be detrimental to seagrasses and their associated plants
and animals. However, since seagrass productivity (i.e., oxygen production due to
photosynthesis) is high, oxygen levels are generally adequate, although low oxygen levels have
been observed in warm, calm waters during the night, when community respiration and additional
oxygen-demanding matter may deplete oxygen reserves (Zieman, 1982). Anaerobic conditions
in the sediments may actually be beneficial to seagrasses (Zieman, 1982); however, extremely
low oxygen concentrations due to excessive loading of oxygen-demanding organic matter will
have a detrimental effect on the seagrass community.
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nonpoint source
coastal contributions
Chemical Alterations:
sediment
water column
biotransformations
Figure 6-5. Conceptual model of processes and effects relating to toxic inputs in southeast Florida coastal communities.
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The waters of mangrove forests are typified by low oxygen concentrations or even anaerobic
conditions. Mangrove trees have adapted to low-oxygen environments by developing
aboveground root systems to bring oxygen to the roots embedded in the anaerobic sediments
(Odum et al., 1982). However, the biotic communities associated with the mangrove root system
can change markedly as a result of changes in oxygen concentrations within the forest.
6.4.5 Light
Corals that possess symbiotic algae (zooxanthellae) respond to both the intensity and spectral
quality of light. Goenaga et al. (1989) and Williams and Bunkley-Williams (1990) suggested that
unprecedented coral bleaching events that occurred in the Caribbean in 1987 may have been due
in part to increases in ultraviolet radiation related to stratospheric ozone depletion. However,
warmer-than-normal seawater temperatures were also suggested as an additional factor. Because
of the light dependence of zooxanthellate corals, these corals are restricted to areas above the
lower limit of the photic zone. The depth of the photic zone depends on the reflectance,
scattering, and absorption of the water column. Suspended sediments and phytoplankton are two
sources of turbidity that can reduce the depth of the photic zone. Although corals and their
zooxanthellae may be photoadapted to existing light regimes (Dustan, 1979), reduction in light
due to turbidity lowers the coral growth rate and complete shading can cause bleaching and death
(Rogers, 1979).
Coral species show varying susceptibility to light reduction (Rogers, 1979). Susceptibility
appears to be related to the ability of the coral polyps to feed on zooplankton and particulate
matter during periods of low light intensity (Rogers, 1979; Peters and Pilson, 1985). Rogers
(1979) hypothesized that Acropora cervicornis was most susceptible to shading because of its
relatively smaller polyp size (i.e., mouth size), which restricted its ability to obtain external
sources of nutrition. However, A cervicornis was a relatively more efficient sediment remover
in sediment experiments (Rogers, 1979). In environments where turbidity is associated with a
high sedimentation rate, the metabolic cost of sediment removal will cause an increase in
respiration that will be compounded during the night when no light is available for photosynthetic
production (Abdel-Salam et al., 1988).
Light penetration may limit seagrass growth when adequate nutrients are available in shallow
areas or in turbid or deep-water areas (Williams, 1987, 1990). The maximum depth of seagrass
growth in an area may be an indication of the depth of penetration of light, but other factors,
such as herbivore grazing pressure, may be involved (Vicente and Rivera, 1982). The stress due
to changes in light levels in mangrove areas is not considered to be important since the mangrove
tree is an emergent plant and is not limited by light levels in the water column. In general, light
levels in mangrove forests are low due to elevated turbidity and color from humic substances
(Odum et al., 1982). However, mangrove community organisms that inhabit the mangrove root
system may be altered as a result of changes in ambient light levels (e.g., attached algae).
6-22
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6.4.6 Salinity
Both low and high salinity may stress coral communities. Low salinity may occur as the result
of freshwater runoff following storms. Brief episodes of low salinity due to stormwater runoff
have been reported to cause loss of zooxanthellae and coral mortality (e.g., Goreau, 1964). Since
stormwater runoff is simultaneously the source of sediment and fresh water, the effects of salinity
and sediment stress (as well as light reduction) are difficult to separate (Johannes, 1975).
Elevated salinity has been observed to cause coral mortality at levels only slightly above normal
(Johannes, 1975). Several Hawaiian species tested could not tolerate salinities greater than 110
percent of normal for more than 2 weeks. Most species tested died within 24 hours when exposed
to salinities 150 percent of normal (Edmondson, 1928, cited in Johannes, 1975).
The common tropical seagrasses tolerate large salinity fluctuations. Zieman (1982) reported acute
salinity tolerances for Thalassia from 3.5 to 60 ppt, but sublethal effects (e.g., grass blade loss
and reduced productivity) at 20 ppt. Zieman (1982) considered Halodule as the most tolerant to
salinity variation, Thalassia as intermediate, and Syringodium and Halophila as least tolerant.
Zieman (1975, 1982) also noted that seagrass beds are sensitive to temperature and salinity
changes. When salinity is low and temperature is high, seagrass productivity and biomass may
decline dramatically.
Mangrove trees are adapted to accommodate fluctuations in salinity through a variety of
mechanisms of salt excretion and salt exclusion (Odum et al., 1982). Although some mangrove
trees may be able to grow in fresh water, they are easily outcompeted by freshwater plants and
trees (Odum and Johannes, 1975). Elevated salinities may restrict mangrove tree growth and
reproduction. Red mangroves (Rizophora) may be limited to soil salinities below 60 to 65 ppt
(Odum et al., 1982). White mangrove (Laguncularia) and black mangrove (Avicennia) appear to
be more tolerant of salinity, with stressed stands observed in areas with soil salinities of 80 ppt
(Odum et al., 1982). Salinity stress has been observed to affect mangrove canopy height, leaf
area index, leaf litter fall, and tree mortality (Cintron et al., 1978). The biotic community
associated with the mangrove root system is likely to be sensitive to smaller salinity fluctuations.
6.4.7 Pathogens, Herbivores, and Predators
Bacteria (Mitchell and Chet, 1975; Peters et al., 1983; Hodgson, 1990) and filamentous
blue-green algae (Antonius, 1981b) have been identified as pathogenic agents in corals. Antonius
(1981a) and Peters (1984) have reviewed pathogen effects on corals. Mitchell and Chet (1975)
observed that corals stressed by elevated concentrations of crude oil, copper sulfate, potassium
phosphate, or dextrose produced copious amounts of mucous and died. However, with the
addition of antibiotics, mortality was not observed, implicating bacteria as the agents of mortality.
Hodgson (1990) extended this interpretation to sediment stress by demonstrating that an antibiotic
could prevent mortality due to sediment deposition. The loss of corals due to pathogenic effects
may result in dramatic changes in coral community structure including fish populations
(Gladfelter, 1982; Goenaga et al., 1989). Based on the laboratory investigations of Mitchell and
Chet (1975) and Hodgson (1990), there appears to be a direct relationship between environmental
6-23
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stress, bacterial infection, and coral mortality. Field observations suggest that environmental links
to pathogenic effects may exist (Peters, 1984), especially for black band disease (Antonius,
1981a, 1981b).
Community interactions are also important in determining community structure. Effects on coral
community structure have been reported due to algal grazing by the black long-spined sea urchin
(Diadema antillarum)-, the territorial behavior of the threespot damsel fish (Pomacentrus
planifrons); herbivorous reef fish (species of parrotfish and surgeonfish); and predation on corals
by fish (species of parrotfish and surgeonfish), a polychaete worm (Hermodice caruncculata), and
the flamingo tongue snail (Cyphoma gibbosum) (Jaap, 1984). The best example of the effects
of these complex interactions involves the large-scale mass mortality of the long-spined sea
urchin. This urchin was abundant on Caribbean reefs before 1983, but the abundance in particular
areas may have depended on fishing intensity on the reefs (Hay, 1984). Areas where reefs were
heavily fished presumably resulted in the reduction of herbivorous fish and fish predators of the
sea urchin (Hay, 1984). However, beginning in 1983, D. antillarum began to die in large
numbers, possibly due to a waterborne pathogenic agent (Lessios, 1988). On reefs where sea
urchin density was high, algal biomass was low and dominated by algal turfs and crustose algae;
macroalgae were not abundant (Carpenter, 1990a). Following the reduction of long-spined sea
urchin density, algal community biomass and macroalgae increased (Carpenter, 1990a).
Interestingly, algal community productivity decreased (Carpenter, 1990a), and although the
numbers of herbivorous fish increased, algal biomass remained high (Carpenter, 1990b). Since
D. antillarum not only preys on settled coral larvae, but also grazes on algae that inhibit coral
larval settlements, the density of this sea urchin may have additional implications for coral
community structure (Sammarco, 1980).
Tropical seagrass distribution, productivity, and biomass may also be affected by herbivores and
pathogens. Herbivores that feed directly on tropical and subtropical seagrasses include parrotfish,
surgeonfish, sea urchins, sea turtles, and manatees. Although much attention has been paid to
the "wasting disease" of the temperate seagrass Zostera, pathogens of tropical and subtropical
seagrasses have received little attention (Zieman, 1982). Barren areas around coral reefs, or
"halos," have been attributed to the grazing action of fish and to the sea urchin Diadema
antillarum (Ogden et al., 1973). Outbreaks of sea urchin (Lytchechinus variegatus) grazing on
seagrasses have been reported for the west coast of Florida (Zieman, 1982). The historical impact
of the formerly large populations of green sea turtles (Chelonia mydas) and manatees (Trichechus
spp.) and the impact on seagrasses due to their decline are virtually unknown (Hay, 1984). One
study in two bays of St. John, in the U.S. Virgin Islands (Williams, 1988b), determined that the
green sea turtle population was grazing near the carrying capacity of the Thalassia bed (i.e., most
of the newly produced leaf mass was being consumed by the turtles). In Florida Bay, beginning
in 1987, a pathogenic protozoan was suspected as the cause of the "wasting disease" of Thalassia
testudinum (Robblee et al., 1991). More than 23,000 ha were reported to be affected, and 4,000
ha were completely lost, with areas in protected basins being affected most severely (Robblee
et al., 1991). However, other factors such as elevated water temperature, recent decline in
frequency of hurricanes, elevated salinity, and chronic hypoxia of the sediments were also noted
as possible causative factors.
6-24
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Lugo et al. (1981) cited herbivore outbreaks as a nonhuman stressor to mangroves. Odum et al.
(1982) reviewed the effect on mangrove trees of herbivores, wood borers, and mangrove
pathogens. Animals that grazed on live mangroves in Florida included deer, crabs, and insects,
such as beetles, moth and butterfly larvae, grasshoppers, and crickets. Reported mangrove
pathogens included species of fungi (Odum et al., 1982). Odum et al. (1982) concluded that
although infestation rates were high, the magnitude of infestation was related to long-term
fluctuations in salinity (increased salinity resulted in more infestation).
Odum et al. (1982) raised the possibility that human interference with water flow could be
involved in the changes in salinity and resultant changes in the wood borer population, and they
recommended further study. Normal annual fluctuations in rainfall could also play an important
role.
6.4.8 Physical Damage and Changes in the Hydric Regime
Severe physical impacts can crush live coral or cause breakage, fractures, or tissue lesions, which
provide areas susceptible to invasion by pathogens (Peters, 1984). The loss of coral cover and
the concomitant loss of substrate complexity can result in changes in the fish community, which
may change over time as the area is recolonized (Dennis and Bright, 1988). The open space
created can also be quickly colonized by benthic algae.
Physical damage and changes in coral community structure have been noted following hurricanes
(e.g., Jaap, 1984; Rogers et al., 1982; Rogers et al., 1983); ship groundings (e.g., Tilmant 1987;
Dennis and Bright, 1988); trampling (e.g., Liddle, 1991, Povey and Keough, 1991); dredging and
channel construction (e.g., Adey et al., 1981); coastal construction (e.g., Rogers, 1982);
recreational activities such as snorkeling, skin diving, and scuba diving (e.g., Tilmant, 1987;
Rogers, 1988); and deployment of boat anchors (e.g., Jaap,1984; Tilmant, 1987; Rogers, 1988).
Physical disturbances to seagrass beds include the destruction caused by storms and hurricanes,
as well as direct losses due to dredge and fill operations and damage due to boat propellers and
anchors. Zieman (1975) concluded that seagrass beds may be the least susceptible of the coastal
marine communities to severe storm damage. The root and rhizome system of seagrass beds is
apparently able to withstand the severe storm waves generated, although detached grass blades
may be washed up on shore in great quantities (Zieman, 1975).
Williams (1988b) estimated the damage rate to seagrass beds at 1.8 percent per year in two bays
in St. John and determined that seagrass recolonization of scars was minimal after a 7-month
period. External physical alterations of the environment may also affect seagrass beds. Zieman
(1982) hypothesized that channelization of drainage in the Florida Everglades may have resulted
in increased salinity of Florida Bay due to rerouting of freshwater flows away from the bay,
resulting in the invasion of the more salinity-tolerant seagrass T. testudinum.
Direct physical damage results in immediate loss of mangrove trees and may affect the structure
of the mangrove along the perimeter of the affected areas. For example, storms and hurricanes
6-25
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may exert extensive physical damage to mangroves. One hurricane in Florida in 1960 (Hurricane
Donna) caused the loss of from 25 to 100 percent of mangrove trees over a 40,000-ha area
(Odum et al., 1982).
Alterations in the hydric regime are an additional source of stress particular to the mangrove
environment. Because the structure and extent of the mangrove system are strongly dependent
on the exchange of fresh seawater, the flushing of fresh water, and the input of fresh sediments,
the mangrove will rapidly respond to physical alterations that increase or decrease marine or
freshwater influences (Lugo et al., 1981; Cintron and Schaeffer-Novelli, 1983). These changes
may be induced by human activity through the construction of roads or dikes or through upland
development, which will alter the pattern of water exchange, and hence salinity, within the
mangrove. These changes may also be caused by natural events such as long-term deposition or
transport of sediments, which would remove or deposit barriers to water exchange, or through
more catastrophic events such as storms and hurricanes. An additional source of stress, not
addressed in previous sections, is the effect of standing water on mangroves. Water levels that
submerge mangrove aerial roots for long periods during the wet season can cause mangrove
mortality (Odum et al., 1982).
Examples of mangrove mortality due to human interference with water exchange in mangrove
areas are numerous. Stream channelization and the construction of large drainage networks may
impair coastal mangroves (Odum et al., 1982; Jimenez et al., 1985). Coastal road construction,
if not properly fitted with drainage culverts, can hinder mangrove water circulation (Zucca, 1982).
Diking and flooding, a technique often used to enhance waterfowl refuges, may also be fatal to
mangroves (Odum et al., 1982). Human encroachment into mangrove areas has an immediate
detrimental effect. Mangrove areas are also lost directly as a result of dredge and fill operations
and the clearing of mangroves for urban and residential development (Odum et al., 1982).
6-26
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Most Significant Factors Affecting Impact Modeling
• Three key resources (mangroves, seagrass beds, coral hard bottoms)
constitute the major coastal aquatic habitats of southeast Florida.
¦ Physical, chemical, and biological processes occurring in the ecosystems
should be subdivided into multiple categories to fully understand each of
the factors affecting habitats and organisms; thus, multiple conceptual
models may be required.
• Issue-specific conceptual models should include perturbation sources,
affected ecosystem resources, processes affecting perturbation exposure,
and processes affecting resource stress.
• Sediments, nutrients, and toxics contributed by point and nonpoint
sources alter water quality by changing light, salinity, and dissolved
oxygen.
• Other complex factors, such as temperature, pathogens and predators, and
physical damage, will also affect the degree and extent of impacts on the
biota in these communities.
• For the communities of southeast Florida, the only way to truly assess
the impact of the POTW discharges and nonpoint source water quality
alterations on the biota of the area is to sample. Without empirical data,
no responsible determination can be made.
6-27
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6-28
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7. DATA ANALYSES
The information in this section was based on available data obtained from various Federal, State,
and local agencies in the southeast Florida study area and from published reports. Particle
deposition was mapped for the POTW outfalls and estimated pollutant loadings for point and
nonpoint sources were compared.
7.1 DECAL Model Application
The impacts of wastewater discharges in coastal waters are largely exhibited in changes to
sediment composition and in subsequent effects on benthic communities (e.g., coral) in the
vicinity of the effluent. In the South Florida study area, six municipal POTWs (Delray Beach,
Boca Raton, Broward, Hollywood, Miami-Dade North, and Miami Central) discharge to the
ocean through submerged outfall diffusers. Because of buoyancy, discharged sewage effluent
rises through the water column and seawater is entrained in the waste plume. Subsequent
transport and dilution of the wastefield are controlled by coastal transport and mixing processes.
Transport processes include tidal oscillations, wind-driven currents, and large-scale circulation
patterns. Tidal motion plays a significant role in distributing the sewage effluent over the tidal
excursion zone. Tidal motions in coastal waters typically follow elliptical paths, with the major
axes paralleling the shoreline. Oscillation periods range from 12 to 25 hours depending on the
relative strength of the major tidal components. For typical tidal velocities (on the order of
6 cm/sec), the major axis of the tidal-excursion ellipse is several kilometers in size. Nontidal
flows are composed of wind-driven (or pressure-driven) currents and large-scale mean
circulation. The wind-driven currents may exhibit significant variation, often reversing direction
in cycles of 4 to 8 days depending on the passage of weather systems. Off the coast of South
Florida, nontidal flows are primarily influenced by the Florida Current.
The DECAL (deposition calculation) model provides a simple computerized tool for predicting
particle deposition and accumulation of organic material in sediments near municipal ocean
outfalls. The model was formulated on the basis of coastal transport, particle transport, and
organic carbon cycles. The model includes the effects of coagulation and settling of effluent
particles and natural material. The DECAL model was originally developed for the Ocean Data
Evaluation System (ODES), which resides on EPA's National Computer Center mainframe
computer at Research Triangle Park, North Carolina.
The input parameters for DECAL include the effluent discharge flow rate, the effluent solids
concentration, the outfall diffuser location and geometry, the density structure and depth of the
water column, the phytoplankton productivity rate, and a simplified description of ocean
currents. Three modeling coefficients are required for computing particle deposition and organic
accumulation in surface sediments: (1) a second-order coagulation/settling rate coefficient,
7-1
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(2) a decomposition rate coefficient for suspended organic material, and (3) an interfacial
removal rate coefficient for sedimented organic material.
DECAL calculations for accumulations of organic materials in sediments can be used for
predicting environmental impacts from the six ocean outfalls in the South Florida study area.
In particular, the model was used to determine the spatial impact of organic accumulation of
waste from these outfalls on coral reef resources in the study area.
To make accurate predictions, the DECAL model requires ocean current velocity data in the
vicinity of the simulated outfall. NO A A; under its SEFLOEII study, recently began collecting
ocean current data near most of the outfalls in the South Florida study area. It was anticipated
that data from the SEFLOE II study would be used for the DECAL modeling exercise; however,
only data from one current meter (near the Broward outfall in the vicinity of Hillsboro Inlet)
were available in time for this analysis. Data from this meter covered the period November 25,
1991, to December 20, 1991, or a duration of about 25 days. Analysis of these data showed
that the current flowed to the north 49.6 percent of the time with a mean velocity of 22.3 cm/s
and to the south 31.2 percent of the time with a mean velocity of 26.2 cm/s. Lee and McGuire
(1972) analyzed 9 months of current data off Boca Raton and reported that the current flowed
to the north 62 percent of the time with a mean velocity of 23.2 cm/s and to the south 31
percent of the time with a mean velocity of 20.1 cm/s. The east-west series indicated currents
to the east 3.5 percent and to the west 3.5 percent of the time with equivalent mean velocities
of 8.2 cm/s. There was very little difference between the literature values of Lee and McGuire
(1972) and the 1991 SEFLOE II data. Since the length of record used by Lee and McGuire
(1972) was much longer than that of the SEFLOE II data, it was decided that their historical data
would be used as input for the DECAL model. The DECAL model was applied separately at
all six POTWs in the study area using the above north-south current velocities. The cross-shore
currents in the east-west direction were considered negligible and were not included in the
DECAL model runs.
Short-term currents are attributed to a semi-diurnal tidal component in both the alongshore (6°
north) and cross-shore (96° north) directions. Normally, tidal current amplitudes are assigned
based on calculations of cumulative variance for periods of less than 1 day. Amplitudes of 35
cm/sec were assigned to both the alongshore and cross-shore directions based on analysis of the
25-day 1991 SEFLOE II data from the current meter at Broward. The computed tidal
amplitudes correlated well with NOAA historical data at the entrance to Miami Harbor, which
indicate an M2 tidal amplitude of about 36 cm/sec. (The M2 tidal constituent is the primary
semi-diurnal frequency associated with the moon's gravitational force.) Phase shifts of tidal
velocities in the longshore and cross-shore directions are taken as 45° and 0°, respectively, and
are considered to represent an average condition of spreading by tidal motion.
Input parameter values for the DECAL model for each of the six POTWs are listed in Table 7-1.
The effluent solids concentration (SSW), effluent discharge rate (Qw), effluent BOD concentration
(BODw), and toxic concentration (TOXJ were determined from discharge monitoring data for
the period July 1990 to July 1991 (see Appendix B). Values for the three modeling coefficients
required by decal are:
7-2
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2.0X10"6 L/mg/day
0.1/day
5.0X10"4 /day
Table 7-1. DECAL Input Data
Parameter
Delray
Boca
Raton
Broward
Hollywood
Miami-Dade
North
Miami
Central
Qw (mJ/sec)
0.635
0.517
2.734
1.604
3.795
5.464
SSw (mg/L)
11.5
4.7
6.6
17.2
19.4
14.8
BODw (mg/L)
10.0
8.0
12.0
10.3
13.1
16.8
TOXw (mg/L)
2.4
0.9
1.0
0.1
0.6
2.9
YAXIS (deg)
0.0
0.0
0.0
0.0
0.0
0.0
XL (km)
6.0
6.0
6.0
6.0
6.0
6.0
YL (km)
16.0
16.0
16.0
16.0
16.0
16.0
X«. Y0 (km)
3.0, 4.0
3.0, 4.0
3.0, 4.0
3.0, 4.0
3.0, 4.0
3.0, 4.0
DL(m)
115
115
115
115
115
115
THETA (deg)
0
0
0
0
0
0
TDEPTH (m)
29.3
27.4
45.7
27.4
32.8
33.5
DEPTH (m)
29.2
27.3
45.6
27.3
32.7
33.4
PTOT (gC/mVday)
1.6
1.6
1.6
1.6
1.6
1.6
SL (mg/L)
0.0
0.0
0.0
0.0
0.0
0.0
PAXIS (deg)
006
006
006
006
006
006
where:
Q.
discharge flow rate (m3/sec)
SSW
effluent solids concentration (mg/L)
BOD.
BOD concentration in effluent (mg/L)
TOX.
toxic parameter concentration in effluent (mg/L)
YAXIS =
Y-axis rotation (clockwise from north) in degrees
XL
study area length along X-axis (km)
YL
study area length along Y-axis (km)
Xo, Y„ =
location of diffuser with respect to the origin (km)
DL
diffuser length (m)
THETA =
orientation of diffuser (degrees)
TDEPTH =
total water column depth (m)
DEPTH =
water depth below pycnocline (m)
PTOT =
phytoplankton productivity (gC/m2/day)
SL
in situ production of BOD (mg/L)
PAXIS =
orientation of principal axis of ocean currents (azimuth from north in degrees)
7-3
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where B is the second-order coagulation/settling rate coefficient, KD is the first-order organic
material decomposition rate coefficient, and KS is the first-order sediment decomposition rate
coefficient.
Results of the DECAL model runs are shown in Figures 7-1 and 7-2. Steady-state distributions
for organic accumulation in sediments were calculated, and contours ranging from 0.2 to 8.0
g/m2 are presented. The two Miami outfalls show the largest accumulation of organic material
in the sediments, as is expected because of their large discharge and high suspended sediment
concentration. The Boca Raton outfall shows the smallest organic accumulation. Coral reefs
in the study area were digitized, and the DECAL results were superimposed over them to
determine the locations where coral resources were most susceptible to impacts from the POTW
outfalls.
The coral reef locations were provided by Dade County and Broward County and are not
available for the entire coastline of the study area. Based on the available data and DECAL
model results, the coral resources (i.e., the shaded areas in Figures 7-1 and 7-2) are impacted
to some degree by organic waste deposition from all the outfalls with the possible exception of
Delray Beach.
7.2 Comparison of Relative Contributions to Water Quality from POTWs and NPS Loadings
Table 7-2 compares the estimated pollutant loadings and concentrations for point (POTW outfall)
and nonpoint sources of pollution. Table 7-2 combines the data presented previously in Tables
4-5 and 5-3. Because the reporting criteria for the POTWs differ from the surface water
parameters typically monitored, comparisons were made for BOD, total phosphorus, and total
nitrogen only.
7.2.1 Comparative Relative Contributions
Comparison of the relative contributions (pounds of pollutant per million gallons of discharge)
shows that the POTWs' contribution is greater than that of the nonpoint component.
7.2.2 Comparative Absolute Contributions
When comparing the absolute contributions of the listed parameters, it can be seen that the
nonpoint source contribution is greater. For only six canal discharges, the BOD, total
phosphorus, and total nitrogen loadings are 82,915 pounds per day, 6,632 pounds per day, and
63,313 pounds per day, respectively. There are eight additional primary canals that discharge
to coastal waters within the study area for which monitoring data are not available. The
drainage basins for these canals exhibit development patterns similar to those associated with the
canals for which there are data. A comparison of the canal discharges to a total loading of
38,439 pounds per day, 7,279 pounds per day, and 49,197 pounds per day (BOD, phosphorus,
and nitrogen, respectively) for all six POTWs within the study area demonstrates that the
nonpoint source component has a greater absolute contribution to water quality impacts when
considering the cumulative contribution of all the drainage canals in the study area.
7-4
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FL0035980 Delray Beach
FL0026344 Boca Raton
FL0031 771 Broward
Kilometers
10
Coral Reef
Organic Accumulation
of Waste Particles
(gm/sq.m)
— 0.200
— 0.500
— 1.000
Figure 7-1. DECAL model results for Delray Beach, Boca Raton, and Broward POTWs.
-------
7-6
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/
FL0026255 Hollywood
FL0032182 Miami—Dade North
FL0024805 Miami Central POTW
Figure 7-2. DECAL model results for Hollywood, Miami-Dade North, and Miami Central POTWs.
-------
7-8
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Table 7-2. Comparison of Point and Nonpoint Source Pollutant Loadings
Site
Row
(mgd)
BOD
(lb/day)
BOD
(lb/10" gal)
Total P
(lb/day)
Total P
Ob/10s gal)
Total N
Ob/day)
Total N
(lb/10' gal)
Del ray
Beach
(PS)
14.5
1,167
80.5
307*
21.2*
2,039*
140.6*
Broward
County
(PS)
62.4
6,201
99.4
1,323*
21.2*
8,773*
140.6*
Boca
Raton
(PS)
11.8
793
67.2
250'
21.2*
1,659*
140.6*
Holly-
wood
(PS)
36.6
3,126
85.4
776*
21.2*
5,146*
140.6*
Miami-
Dade
(north)
(PS)
86.6
9,576
110.5
1,512
17.5
7,936
91.6
Miami-
Dade
(central)
(PS)
124.7
17,576
140.9
3,111
24.9
23,644
189.6
1
(NPS)
0.064
0.97
15.2
0.04
0.62
0.8
12.5
2
(NPS)
2,761
30,802
11.2
2,228
0.82
2,383
8.5
3
(NPS)
1,603
2,970
1.9
543
0.34
2,038
1.3
4
(NPS)
924
11,272
12.2
267
0.29
9,907
10.7
5
(NPS)
2,562
28,659
11.2
2,785
1.09
21,020
8.2
6
(NPS)
750
9,211
12.3
749
1.5
6,764
9.0
PS = point source; NPS = nonpoint source
' There were no data for these facilities for total P and total N; the values were derived by averaging the concentrations
for the two Miami-Dade facilities.
7-9
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7-10
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8. DISCUSSION
Several factors need to be evaluated when considering the contributions of point and nonpoint
pollution in the study area, including the lack of consistent, good-quality monitoring data for
nutrients, toxics, and sediment loading, and additional research needs.
8.1 Limitations of This Study
The point sources examined here were very specific: the six publicly owned sewage treatment
facilities discharging to coastal waters. There are other point sources of pollution within the
study area that were not within the scope of this task. Some of these are listed in Table 8-1.
In addition, there may be nutrient and other pollutant inputs in groundwaters discharging to the
nearshore area (Lapointe et al., 1990). However, the POTW ocean outfalls have the potential to
have the most impact on the coral ecosystem and other benthic communities because of their
proximity to the habitat.
Because the nonpoint pollutants were measured in the inshore environment, it is difficult to know
what percentage, if any, actually are transported to the reef areas in quantities significant enough
to have an impact. Assuming a worst case—all nonpoint source pollutants are transported
offshore—their contribution would be greater than that of the point sources. However, this is
probably not the case. Heavy metals (while not evaluated here, a significant component of urban
runoff) most likely bind to the sediment and fall out of suspension in the canals or close to shore.
The hydrodynamics of the intracoastal system prevent many of the pollutants from migrating
offshore; however, in the absence of a comprehensive monitoring and modeling program, this is
difficult to evaluate.
Most important, the lack of comprehensive data on nonpoint source pollution in the area makes
it difficult to effectively evaluate the contribution of such pollution to offshore impacts. Because
the nonpoint sources of pollution can be controlled through both structural measures, such as
stormwater treatment facilities, and nonstructural controls, such as watershed management
planning, landscaping ordinances, and public education programs, their contribution to water
quality problems in the study area can be effectively controlled.
For the point sources examined in this study, monitoring for nitrogen and phosphorus is not
required for all of the POTWs; therefore, nutrient loadings cannot be determined. Without data
on nutrient loadings, the impacts of the point source discharges on the sensitive biological
communities cannot be fully ascertained.
Furthermore, no critical analyses of the dynamics of the POTW discharges have been conducted
since the SEFLOE I study in 1987-88. The SEFLOE II study is currently being conducted, but
data from the study are not yet available. Current data from the Broward County outfall could
not be used. The SEFLOE studies have not been fully successful in determining the impacts of
8-1
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Table 8-1. Other Private and Public Wastewater Treatment
Facilities in Southeast Florida (City of Broward)
NPDES No.
Facility Name
RWDLAT
RWDLONG
PEMBROKE PINES CS
FL0027367
PLANTATION SOUTH STP
260606
801404
FL0027928
PLANTATION NORTH
260836
801404
CORAL SPRINGS WEST
260832
800602
CORAL SPRINGS EAST
260832
800602
MIRAMAR COLL SYS
B.C.U.P. #3
DEERFIELD BCH COLL SYS
OAKLAND PARK CS
261130
800750
FL0037559
SUNRISE STP NO. 1
POMPANO BCH WW COLLN SYS
FL0021342
EXECUTIVE AIRPORT WWTP
260712
800812
RIVERLAND ROAD WWTP
SIXTH STREET SLUDGE
260800
801000
FL0020524
CORAL RIDGE WWTP
261030
800640
FL0020362
PORT EVERGLADES STP
260712
800812
MARGATE STP
GULFSTREAM STP
BONAVENTURE CS
FERNCREST STP
FL0033499
DAVIE STP
WESTON CS
FL0029211
COOPER CITY STP
LAUDERHILL WEST WWTP
260832
800602
LAUDERHILL LAKES CS
260908
801307
MODERN PCF
FL0020320
NORTH LAUDERDALE STP
261000
800500
DANIA CS
PALMDALE CS
FL0037575
SUNRISE STP NO. 3
FL0037079
SUNRISE STP 2
255617
800703
WEST TAMARAC STP
CORAL SPGS ID STP
the POTW discharges on water quality. The attempts to determine the degree of bacterial die-off
from exposure to salt water were largely inconclusive. To date, there are no studies addressing
the impact of residual chlorine, contained in the effluent, on the marine environment off southeast
Florida.
The SEFLOE I study examined plume direction for only 2 days. Oceanographic studies have
shown that current reversals occur on the order of every 7 to 10 days along the southeast Florida
coast. These current reversals, also known as spin-off eddies, are the primary force affecting the
8-2
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coastal waters in this area. They advect Florida Current water onto the shelf and move coastal
waters eastward off the shelf. The residence time of the waters located on the "coastal strip" (the
area between the west edge of the Florida Current and the shoreline) is approximately 1 week.
To fully understand what biological communities are being impacted and the extent of the impact,
comprehensive current data would need to be collected and then modeled.
8.2 Other Issues
Recently, an unusually high number of algal blooms have been reported by scientists on the
southeast coast of Florida at Palm Beach, Delray Beach, Boca Raton, Jupiter, and Juno Beach
(Stephen M. Blair, Dade County Department of Environmental Resource Management, personal
communication). These blooms contain an unidentified green alga, Codium sp. Little is known
about the ecology of this species. Most algal blooms occur as the result of short-term
advantageous changes in the environment (e.g., temperature variations or nutrient enrichment).
The environmental factors needed by Codium sp. to increase in biomass are present in these
localized coastal areas and may lead to serious problems for the coral community. These blooms
have occurred only in the last 3 to 4 years, with the size and area of the blooms increasing. A
cyanobacterium, Microcoleus lyngbyaceus, has appeared in blooms in the Indian River, Florida
Keys, and coastal waters of Dade County.
Minor changes in terrestrial runoff, increased sewer outfalls, upwelling, increased nutrients, and
alterations in the currents or tidal pattern can change coastal water quality and promote algal
blooms. The Palm Beach coastal area is also a suitable habitat for Codium sp. to flourish,
possibly because upwelling of the Florida Current transports nutrients and deep-water Codium
sp. populations up to the surface waters, increasing the potential for blooms to occur. Although
at this time a definite cause is unknown, scientific studies need to be undertaken to determine
the cause(s) of the blooms, the impact of Codium sp. and cyanobacteria on the coral
communities, and the direction of ocean currents off southeast Florida.
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9. REFERENCES
Abdel-Salam, H., J.W. Porter, and B.G. Hatcher. 1988. Physiological effects of sediment
rejection on photosynthesis and respiration in three Caribbean reef corals. Proc. Sixth Intern.
Coral Reef Symp., Townsville, Australia 2:285-292.
Acevedo, R. 1991. Preliminary observations on effects of pesticides carbaryl, naphthol, and
chlorpyrifos on planulae of the hermatypic coral Pocillopora damicornis. Pac. Sci. 45:287-289.
Adey, W.H., C.S. Rogers, and R.S. Steneck. 1981. The south St. Croix reef: A study of reef
metabolism as related to environmental factors and an assessment of environmental management.
Prepared for the Department of Conservation and Cultural Affairs, Government of the U.S. Virgin
Islands.
AJongi, D.M. 1989. The role of soft-bottom benthic communities in tropical mangrove and coral
reef ecosystems. CRC Critical Rev. Aquat. Sci. 1:243-280.
Antonius, A. 1981a. Coral reef pathology: a review. Proc. Fourth Intern. Coral Reef Symp.,
Manila, Philippines, 2:3-6.
Antonius, A. 1981b. The "band" diseases in coral reefs. Proc. Fourth Intern. Coral Reef Symp.,
Manila, Philippines 2:7-14.
Bak, R.P.M. 1987. Effects of chronic oil pollution on a Caribbean coral reef. Mar. Pollut. Bull.
18:534-539.
Bak, R.P.M., and J.H.B.W. Elgershuizen. 1976. Patterns of oil-sediment rejection in corals.
Mar. Biol. 37: 105-113.
Bane, J.M., and D.A. Brooks. 1979. Gulf Stream meanders along the continental margin from
the Florida Straits to Cape Hatteras. Geophys. Res. Lett. 6: 280-282.
Banner, A.H. 1974. Kaneohe Bay, Hawaii: Urban pollution and a coral reef ecosystem. Proc.
Second Intern. Coral Reef Symp., Australia 1:685-702.
Baranov, Y.I. 1967. Studies of vortices in the Gulf Stream frontal zones. Oceanology 7 (1):
61-65.
Bathen, K.H. 1968. A descriptive study of the physical oceanography of Kaneohe Bay, Oahu,
Hawaii. Tech. Rep. 14, Hawaii Institute of Marine Biology, Univ. of Hawaii, Kaneohe, HI.
9-1
-------
Birkeland, C. 1977. The importance of rate of biomass accumulation in early successional
stages of benthic communities to the survival of coral recruits. Proc. Third Intern. Coral Reef
Symp., Miami, Florida 2:15-21.
Brock, R.E., C. Lewis, and R.C. Wash. 1979. Stability and structure of a fish community on
a coral patch reef in Hawaii. Mar. Biol. 54: 281-292.
Brooks, D.A. 1975. Wind-forced Continental Shelf waves in the Florida Current. Ph.D.
dissertation. Univ. of Miami, FL.
Brooks, D.A., and J.M. Bane. 1983. Gulf Stream meanders off North Carolina during winter
and summer, 1979. J. Geophys. Res. 88 (C8): 4633-4650.
Brooks, I. 1979. Fluctuations in the transport of the Florida Current at periods between tidal
and two weeks. J. Phys. Oceanogr. 9: 1048-1053.
Brooks, N.H. 1960. Diffusion of sewage effluent in an ocean current, pp. 246-267. In Proc.
1st International Conf on Waste Disposal in the Marine Environment, Berkeley, CA, July 1959.
Pergamon Press, Paris, France.
Carmody, D.J., J.B. Pearce, and W.E. Yasso. 1973. Trace metals in sediments of New York
Bight. Mar. Poll. Bull. 4: 132-135.
Carpenter, R.C. 1990a. Mass mortality of Diadema antillarum. D. Long-term effects on sea
urchin population dynamics and coral reef algal communities. Mar. Biol. 104:67-77.
Carpenter, R.C. 1990b. Mass mortality of Diadema antillarum. 13. Effects on population densities
and grazing intensity of parrotfishes and surgeonfishes. Mar. Biol. 104:79-86.
Cintron, G., A.E. Lugo, D.J. Pool, and G. Morris. 1978. Mangroves of arid environments in
Puerto Rico and adjacent islands. Biotropica 10:110-121.
Cintron, G., and Y. Schaeffer-Novelli. 1983. Mangrove forests: Ecology and response to
natural and man-induced stressors. In Coral reefs, seagrass beds and mangroves: Their
interaction in the coastal zones of the Caribbean, pp. 87-113. Report of a workshop held at West
Indies Laboratory, St. Croix, U.S. Virgin Islands, May 1982. UNESCO Rep. Mar. Sci. no. 23.
Clough, B.F., K.G. Boto, and P.M. Attiwill. 1983. Mangroves and sewage: a re-evaluation. In
Biology and ecology of mangroves, ed. H.J. Teas, pp. 151-161. Dr. W. Junk Publishers, The
Hague.
Costello, M.J. and J.C. Gamble. 1992. Effects of sewage sludge on marine fish embryos and
larvae. Mar. Environ. Res. 33:49-74.
9-2
-------
Cross, J.N. 1985. Fin erosion among fishes collected near a southern California municipal
wastewater outfall (1971 - 1982). Fish. Bull. 83: 195-206.
Culic, P. 1984. The effects of 2,4-D on the growth of Rhizophora stylosa Griff, seedlings. In
Physiology and Management of Mangroves, ed. H.J. Teas, pp. 57-63. Dr. W. Junk Publishers,
The Hague.
CSA. 1990. Synthesis of available biological, geological, chemical, socioeconomic, and cultural
resource information for the South Florida area. Prepared by Continental Shelf Associates, Inc.,
for U.S. Department of the Interior, Minerals Management Service, Atlantic OCS Region. OCS
Study MMS 90-0019.
Dahl, A.L., B.C. Patten, S.V. Smith, and J.C. Zieman, Jr. 1974. A preliminary coral reef
ecosystem model. Atoll Res. Bull. 172: 7-36.
D'Amato, R., and T.N. Lee. 1977. A kinematic model of the City of Miami ocean outfall plume
behavior. Ecol. Model. 3:227-243.
DeFerrari, H.A. 1970. Dynamically induced fluctuations in acoustic transmissions. Institute of
Marine Science Final Report to Naval Ship Systems Command.
De Freese, D.E. 1991. Threats to biological diversity in marine and estuarine ecosystems of
Florida. Coastal Management 19: 73-101.
Dennis, G.D., and T.J. Bright. 1988. The impact of a ship grounding on the reef fish
assemblage at Molasses Reef, Key Largo National Marine Sanctuary, Florida. Proc. Sixth Intern.
Coral Reef Symp., Townsville, Australia 2:293-298.
DeRycke, R.J., and P.K. Rao. 1973. Eddies along a Gulf Stream boundary viewed from a very
high resolution radiometer. J. Phys. Ocean. 3 (4): 490-492.
Dfaz-Piferrer, M. 1964. The effects of an oil on the shore of Guanica, Puerto Rico. (Abstract).
Deep-sea Res. 11:855-856.
Dierberg, F.E. 1991. Non-point source loadings of nutrients and dissolved organic carbon from
an agricultural-suburban watershed in east central Florida. Wat. Res. 25:363-374.
Dodge, R.E. 1987. Growth rate of stony corals of Broward County, Florida: Effects from past
beach renourishment projects. Prepared for Broward County Office of Natural Resource Protec-
tion, Erosion Prevention District, Fort Lauderdale, Florida.
9-3
-------
Dodge, R.E., S. Hess, and C. Messing. 1991. Final report: Biological monitoring of the John
U. Lloyd Beach renourishment: 1989. Prepared for Broward County Board of County
Commissioners, Erosion Prevention District of the Office of Natural Resource Protection, Fort
Lauderdale, FL.
Duing, W. 1975. Synoptic studies of transients in the Florida Current. J. Mar. Sci. 33 (1): 53-73.
Duing, W., and D. Johnson. 1971. Southward flow under the Florida current. Science 173: 428-
430.
Duing, W., C.N.K. Mooers, and T.N. Lee. 1977. Low frequency variability in the Florida
Current and relation to atmospheric forcing from 1972 to 1974. J. Mar. Res. 35 (1).
Dustan, P. 1979. Distribution of zooxanthellae and photosynthetic chloroplast pigments of the
reef-building coral Montastrea annularis Ellis and Solander in relation to depth on a West Indian
coral reef. Bull. Mar. Sci. 29:79-95.
Edmond, T.D., G.E. Schaiberger, and C.P. Gerba. 1978. Detection of enteroviruses near deep
marine sewage outfalls. Mar. Pollut. Bull. 9:246-249.
Endean, R. 1976. Destruction and recovery of coral reef communities. In Biology and geology
of coral reefs, Vol. 3, Biology, ed. O.A. Jones and R. Endean, pp. 215-254. Academic Press,
London.
Evans, E.C. 1977. Microcosm responses to environmental perturbance. Helgol. Meeres. 30:178-
191.
Florida Department of Commerce. 1988. Florida visitor study, 1988. Tallahassee, FL.
Ford, W.L., J.R. Longard, R.E. Banks. 1952. On the nature, occurrence and origin of cold low
salinity water along the edge of the Gulf Stream. J. Mar. Res. 11: 281-293.
Gladfelter, W.B. 1982. White-band disease in Acropora palmata: Implications for the structure
and growth of shallow reefs. Bull. Mar. Sci. 32:639-643.
Glynn, P.W., L.S. Howard, E. Corcoran, and A.D. Freay. 1984. The occurrence and toxicity of
herbicides in reef building corals. Mar. Pollut. Bull. 15:370-374.
Glynn, P.W., A.M. Szmant, E.F. Corcoran, and S.V. Cofer-Shabica. 1989. Condition of coral
reef cnidarians from the northern Florida reef tract: pesticides, heavy metals, and
histopathological examination. Mar. Pollut. Bull. 20:560-576.
9-4
-------
Goenaga, C., V.P. Vicente, and R.A. Armstrong. 1989. Bleaching induced mortalities in reef
corals from La Parguera, Puerto Rico; a precursor of change in the community structure of coral
reefs? Carib. J. Sci. 25:59-65.
Goh, B.P.L. 1991. Mortality and settlement success of Pocillopora damicornis planula larvae
during recovery from low levels of nickel. Pacif Sci. 45:276-286.
Goldberg, W.M. 1973. The ecology of the coral-octocoral communities off the southeast Florida
coast: geomorphology, species composition, and zonation. Bull. Mar. Sci. 23:465-488.
Goldberg, W.M. 1984. Long term effects of beach restoration in Broward County, Florida: A
three year overview. Coral Reef Associates, Inc., Florida International University, Miami,
Florida.
Goreau, T.F. 1964. Mass expulsion of zooxanthellae from Jamaican reef communities after
Hurricane Flora. Science 145:383-386.
Grigg, R.W., and S.J. Dollar. 1990. Natural and anthropogenic disturbance on coral reefs. In
ecosystems of the world: Coral reefs, ed. Z. Dubinsky, pp. 439-452. Elsevier Publ., New York.
Hallock, P., and W. Schlager. 1986. Nutrient excess and the demise of coral reefs and carbonate
platforms. Palaios 1:389-398.
Hatcher, B.G., R.E. Johannes, and A.I. Robertson. 1989. Review of research relevant to the
conservation of shallow tropical marine ecosystems. Oceanogr. Mar. Biol. Annu. Rev. 27: 337-
414.
Hay, M.E. 1984. Patterns of fish and urchin grazing on Caribbean coral reefs: Are previous
results typical? Ecology 65:446-454.
Hazen and Sawyer, P.C. 1990. Southeast Florida Outfalls Experiment (SEFLOE) for the City
of Hollywood wastewater treatment plant outfall rft. Prepared by Hazen and Sawyer, P.C.
Engineers, for City of Hollywood.
Hodgins, H.O., B.B. McCain, and J.W. Hawkes. 1977. Marine fish and invertebrate diseases,
host disease resistance, and pathological effects of petroleum. In Effects of petroleum on arctic
and subarctic marine environments and organisms, Volume 2, ed. D.C. Malins, pp. 95-173.
Academic Press, New York.
Hodgson, G. 1990. Tetracycline reduces sedimentation damage to corals. Mar. Biol. 104:493-
496.
9-5
-------
Hoi-Chaw, L. 1984. A review of oil spills with special references to mangrove environment.
In Fate and effects of oil in the mangrove environment, ed. L. Hoi-Chaw and F. Meow-Chan, pp.
5-19. University Sains Malaysia, Palau Pinan.
Hoi-Chaw, L., L. Chin-Peng, and L. Kheng-Theng. 1984. Effects of naturally and chemically
dispensed oil on invertebrates in mangrove swamps. In Fate and effects of oil in the mangrove
environment, ed. L. Hoi-Chaw and F. Meow-Chan, pp. 101-119. University Sains Malaysia,
Palaw Pinan.
Hubbard, D.K. 1987. A general review of sedimentation as it relates to environmental stress
in the Virgin Islands Biosphere reserve and the Eastern Caribbean in general. Biosphere
Reserve research report no. 20. Virgin Islands Resource Mangagement Cooperative/National Park
Service.
Hubbard, J.A.E.B. and Y.P. Pocock. 1972. Sediment rejection by recent scleractinian corals: a
key to palaeo-environmental reconstruction. Geol. Rdsch. 61: 598-626.
Hudson, J.H. 1981. Growth rates in Montastraea annularis: A record of environmental change
in Key Largo Coral Reef Marine Sanctuary, Florida. Bull. Mar. Set 31:444-459.
Jaap, W. 1984. The ecology of the south Florida coral reefs: A community profile. Prepared for
U.S. Dept. of the Interior, Fish and Wildlife Service and Minerals Management Service.
FWS/OBS-82/08.
Jaap, W.C., and P. Hallock. 1990. Coral reefs. In Ecosystems of Florida, ed. R.L. Myers and
J.J. Ewel, pp. 574-616. University of Central Florida Press, Orlando, FL.
Jackson, J.B.C., J.D. Cubit, B.D. Keller, V. Batitsta, K. Burns, H.M. Caffey, R.L. Caldwell, S.D.
Garrity, C.D. Getter, C. Gonzalez, H.M. Guzman, K.W. Kaufmann, A.H. Knap, S.C. Levings,
M.J. Marshall, R. Steger, R.C. Thompson, and E. Weil. 1989. Ecological effects of a major oil
spill on Panamanian coastal marine communities. Science 243:37-44.
Jimenez, J.A., R. Martfnez, and L. Encarnacion. 1985. Massive tree mortality in a Puerto Rican
mangrove forest. Carib. J. Sci. 21:75-78.
Johannes, R.E. 1975. Pollution and degradation of coral reef communities. In Tropical marine
pollution, ed. E.G.F. Wood and R.E. Johannes, pp. 13-15. Elsevier, Amsterdam.
Johannes, R.E., and S.B. Betzer. 1975. Introduction: marine communities respond differently to
pollution in the tropics than at higher latitudes. In Tropical marine pollution, ed. E.J.F. Wood and
R.E. Johannes, pp. 1-12. Elsevier, Amsterdam.
Johannes, R.E., W.J. Wiebe, C.J. Crossland, D.W. Rimmer, and S.V. Smith. 1983. Latitudinal
limits of coral reef growth. Mar. Ecol. Prog. Ser. 11:105-111.
9-6
-------
Kielman, J., and W. Duing. 1974. Tidal and sub-inertial fluctuations in the Florida Current. J.
Phys. Oceanogr. 4: 227-236.
King, D., and M.P. O'Brien. 1971. The environment of marine operations at Miami-Pompano
Beach, Tampa Bay entrance, and Galveston Bay entrance. Coastal and Oceanographic
Engineering Dept., Univ. of Fl. Publ. 71/001.
Kinsey, D.W. 1973. Small-scale experiments to determine the effects of crude oil films on gas
exchange over the coral back-reef at Heron Island. Environ. Pollut. 4:167-182.
Kinsey, D.W., and P.J. Davies. 1979. Effects of elevated nitrogen and phosphorus on coral reef
growth. Limnol. Oceanogr. 24: 935-940.
Lapointe, B.E., J.D. O'Connell, and G.S. Garrett. 1990. Nutrient couplings between on-site
sewage disposal systems, groundwaters, and nearshore surface waters of the Florida Keys.
Biogeochem. 10:289-307.
Larsen, J.C., and T.B. Sanford. 1985. Florida Current volume transports from voltage
measurements. Science 221: 302-304.
Leaman, K.D., R.L. Molinari, and P.S. Vertes. 1987. Structure and variability of the Florida
Current at 27 N: April 1982 - July 1984. J. Phys. Oceanogr. 17 (5): 565-583.
Lee, T.N. 1975. Florida Current spin-off eddies. Deep-Sea Res. 22:753-765.
Lee, T.N., and L.P. Atkinson. 1983. Low-frequency current and temperature variability from Gulf
Stream frontal eddies and atmospheric forcing along the Southeast U.S. Continental Shelf. J.
Geophys. Res. 88 (C8): 4541-4567.
Lee, T.N., L.P. Atkinson, and R. Legeckis. 1981. Observations of a Gulf Stream frontal eddy on
the Georgia continental shelf, April, 1977. Deep-Sea Res. 28 (4): 347-378.
Lee, T.N., and D.A. Mayer. 1977. Low-frequency current variability and spin-off eddies along
the shelf off southeast Florida. J. Mar. Res. 35 (1): 193-220.
Lee, T.N., and J.B. McGuire. 1972. An analysis of marine waste disposal in southeast Florida's
coastal waters. Advances in Water Pollution Research, Sixth International Conference, Jerusalem,
Israel.
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.
Lee, T.N., F.A. Schott, and R. Zantopp. 1985. Florida Current: Low-frequency variability as
observed with moored current meters during April 1982 to June 1983. Science 227:298-302.
9-7
-------
Lee, T.N., and E. Waddell. 1983. On Gulf Stream variability and meanders over the Blake
Plateau at 30 N. J. Geophys. Res. 88 (C8): 4617-4631.
Lee, T.N., and E. Williams. 1988. Wind-forced transport fluctuations of the Florida Current.
Phys. Ocean. 18 (7): 937-946.
Legeckis, R. 1979. Satellite observations of the influence of bottom topography on the seaward
deflection of the Gulf Stream off Charleston, South Carolina. J. Phys. Oceanogr. 9: 483-497.
Lewis, J.B. 1960. The coral reefs and coral communities of Barbados, West Indies. Can. J.
Zool 38:1133-1145.
Lewis, J.B. 1985. Groundwater discharge onto coral reefs, Barbados (West Indies). Proc. Fifth
Intern. Coral Reef Congress, Tahiti, pp. 477-481.
Lewis, J.B. 1987. Measurements of groundwater seepage flux onto a coral reef: Spatial and
temporal variations. Limnol. Oceanogr. 32:1165-1169.
Lewis, R.R. IE. 1983. Impact of oil spills on mangrove forests. In Biology and ecology of
mangroves, ed. H.J. Teas, pp. 171-183. Dr. W. Junk Publishers, The Hague.
Liddle, M.J. 1991. Recreation ecology: Effects of trampling on plants and corals. Tree 6:13-
17.
Lighty, R.G. 1977. Relict shelf-edge holocene coral reef: Southeast coast of Florida. Proc.
Third Int. Coral ReefSymp., Miami, Florida 2:215-221.
Littler, M.M., and D.S. Littler. 1985. Factors controlling relative dominance of primary
producers on biotic reefs. Proc. 5th Coral Reef Congr., Tahiti 4:35-39.
Loya, Y. 1976. Effects of water turbidity and sedimentation on the community structure of
Puerto Rican corals. Bull. Mar. Sci. 26:450-456.
Loya, Y., and B. Rinkevich. 1980. Effects of oil pollution on coral reef communities. Mar.
Ecol. Prog. Ser. 3:167-180.
Lugo, A.E., G. Cintron, and C. Goenaga. 1981. Mangrove ecosystems under stress. In Stress
effects on natural ecosystems, ed. G.W. Barret and R. Rosenberg, pp. 129-152. John Wiley and
Sons, New York.
Mahoney, J.B., F.H. Midlige, and D.G. Deuel. 1973. A fin rot disease of marine and euryhaline
Fishes in the New York Bight. Trans. Amer. Fish. Soc. 102: 596-605.
9-8
-------
Marszalek, D.S. 1980. Environmental impact on a coral community from the Dade County beach
erosion control and hurricane surge protection project. Prepared for Metro-Dade Department
of Environmental Resources Management. Miami, FL.
Marszalek, D.S. 1981. Impact of dredging on a subtropical reef community, southeast Florida,
U.S.A. Proc Fourth Intern. Coral Reef Symp., Manila 1:148-153.
Marszalek, D.S. 1987. Sewage and eutrophication. In Human impacts on coral reefs: Facts
and recommendations, ed. B. Salvat, pp. 77-90. Antenne de Tahiti Musum E.P.H.E., Papetoai,
Moorea, French Polynesia.
Mayer, D.A., K.D. Leaman, and T.N. Lee. 1984. Tidal motions in the Florida Current. J. Phys.
Oceanogr. 14 (10): 1551-1559.
McClain, C.R., L.J. Pietrafesa, and J.A. Yoder. 1984. Observations of Gulf Stream-induced and
wind-driven upwelling in the Georgia Bight using mean color and infrared imagery./. Geophys.
Res. 89: 3705-3723.
McCloskey, L.R., and R.H. Chesher. 1971. Effects of man-made pollution on the dynamics of
coral reefs. In Scientists-in-the-sea, ed. J.W. Miller et al., pp. 229-237. U.S. Department of the
Interior, Washington, DC.
McDermott, D.J., G.V. Alexander, D.R. Young, and A.J. Mearns. 1976. Metal contamination of
flatfish around a large submarine outfall. J. Wat. Poll. Control Fed. 48(8): 1913-1918.
McDermott-Ehrlich, D., M.J. Sherwood, T.C. Heesen, D.R. Young, and A.J. Mearns. 1977.
Chlorinated hydrocarbons in Dover sole, Microstomuspacificus: local migrations and fin erosion.
Fish. Bull. 75: 513-517.
McDermott-Ehrlich, D., D.R. Young, and T.C. Heesen. 1978. DDT and PCB in flatfish around
southern California municipal outfalls. Chemosphere 6: 453-461.
McRoy, C.P. 1983. Nutrient cycles in Caribbean seagrass ecosystems. In Coral reefs, seagrass
beds, and mangroves: Their interaction in the coastal zones of the Caribbean, pp. 69-79. Report
of a workshop held at West Indies Laboratory, St. Croix, U.S. Virgin Islands, May 1982.
UNESCO Rep. Mar. Sci. no. 23.
Mearns, A.J., and M. Sherwood. 1974. Environmental aspects of fin erosion and tumors in
southern California Dover sole. Trans. Amer. Fish. Soc. 103: 799-810.
Metro Dade County Planning Department. 1986. Biscayne Bay Aquatic Preserve management
plan. Draft. Metro Dade County Planning Department, Miami, FL.
9-9
-------
Mitchell, R., and I. Chet. 1975. Bacterial attack of corals in polluted seawater. Microb. Ecol.
2:227-233.
Mooers, C.N.K., and D. Brooks. 1974. Several-day to several-week fluctuations in the Florida
Current. Tran. Amer. Geophys. Union 54 (4): 311.
Mooers, C.N.K., and D. Brooks. 1977. Fluctuations in the Florida Current, Summer 1970.
Deep-Sea Res. 24: 399-425.
Molinari, R.L., W.D. Wilson, and K. Leaman. 1985. Volume and heat transports of the Florida
Current: April 1982 through August 1983. Science 227: 295-297.
Niiler, P.P., and W.S. Richardson. 1973. Seasonal variability in the Florida Current. J. Mar.
Sci. 31 (3): 144-167.
Odum, W.E., and R.E. Johannes. 1975. The response of mangroves to man-induced
environmental stress. In Tropical marine pollution, ed. E.J.F. Wood and R.E. Johannes, pp. 52-
62. Elsevier Oceanography Series, Amsterdam, Netherlands.
Odum, W.E., C.C. Mclvor, and T.J. Smith III. 1982. The ecology of the mangroves of South
Florida: A community profile. U.S. Fish and Wildlife Service, Office of Biological Services,
Washington, DC. FWS/OBS-81/24.
Odum, W.E., and C.C. Mclvor. 1990. Mangroves. In Ecosystems of Florida, ed. R.L. Myers
and J.J. Ewel, pp. 517-548. University of Central Florida Press, Orlando, FL.
Ogden, J.C., R. Brown, and N. Salesky. 1973. Grazing by the echinoid Diadema antillarum
Philippi. Formation of halos around West Indian patch reefs. Science 182:715-717.
Parr, A.E. 1937. Report on hydrographic observations at a series of anchor stations across the
Straits of Florida. Bull. Bingham Ocean. Coll. 6 (3): 1-62.
Pastorok, R.A., and G.R. Bilyard. 1985. Effects of sewage pollution on coral-reef communities.
Mar. Ecol Prog. Ser. 21: 175-189.
Pearson, R.G. 1981. Recovery and recolonization of coral reefs. Mar. Ecol. Prog. Ser. 4: 105-
122.
Peters, E.C. 1984. A survey of cellular reactions to environmental stress and disease in
Caribbean scleractinian corals. Helgol. Meeresunters. 37:113-137.
Peters, E.C. 1992. Diseases of other invertebrate phyla: Porifera, Cnidaria, Ctenophora,
Annelida, Echinodermata. In Pathobiology of marine and estuarine organisms, ed. J. A. Couch
and J.W. Fournie, pp. 388-444. CRC Press Inc., Boca Raton, FL.
9-10
-------
Peters, E.C., P.A. Meyers, P.P. Yevich, and N.J. Blake. 1981. Bioaccumulation and
histopathological effects of oil on a stony coral. Mar. Pollut. Bull 12:333-339.
Peters, E, J.J. Oprandy, and P.P. Yevich. 1983. Possible causal agent of "white band" disease
in Caribbean Acroporid corals. J. Invertebr. Pathol 41:394-396.
Peters, E.C., and M.E.Q. Pilson. 1985. A comparative study of the effects of sedimentation on
symbiotic and asymbiotic colonies of the coral Astrangia danae Milne Edwards and Haime 1849.
J. Exp. Mar. Biol. Ecol. 92:215-230.
Pietrafesa, L.J., and G.S. Janowitz. 1980. On the dynamics of the Gulf Stream front in the
Carolina Capes. Stratified Flow: Second Int. Symp. on Stratified Flows, Tapin. 184-197.
Pillsbury, J.E. 1890. The Gulf Stream—a description of methods employed in the investigation,
and the results of the research. U.S. Coast and Geodetic Survey. Report for 1890. Appendix No.
10, pp. 461-620.
Povey, A., and M.J. Keough. 1991. Effects of trampling on plant and animal populations on
rocky shores. Oikos 61:355-368.
Proni, J.R., and W.P. Dammann. 1989. Final Report: Southeast Florida Outfall Experiments
(SEFLOE). National Oceanic and Atmospheric Administration, Atlantic Oceanographic and
Metereological Laboratory, Miami, FL.
Richmond, R.H., and C.L. Hunter. 1990. Reproduction and recruitment of corals: Comparisons
among the Caribbean, the Tropical Pacific, and the Red Sea. Mar. Ecol. Prog. Ser. 60:185-203.
Robblee, M.B., T.R. Barber, P.R. Carlson, Jr., M.J. Durako, J.W. Fourqurean, L.K. Muehlstein,
D. Porter, L.A. Yarbro, R.T. Zieman, and J.C. Zieman. 1991. Mass mortality of the tropical
seagrass Thalassia testudinum in Florida Bay (USA). Mar. Ecol Prog. Ser. 71:297-299.
Rogers, C.S. 1979. The effect of shading on coral reef structure and function. J. Exp. Mar.
Biol. Ecol. 41:269-288.
Rogers, C.S. 1982. The marine environments of Brewers Bay, Perseverance Bay, Flat Cay and
Saba Island, St. Thomas, U.S.V.I., with emphasis on coral reefs and seagrass beds. (November
1978-July 1981). Department of Conservation and Cultural Affairs, Government of the Virgin
Islands.
Rogers, C.S. 1988. Recommendations for long-term assessment of coral reefs: U.S. National
Park Service regional program. Proc. Sixth Intern. Coral Reef Symp., Townsville, Australia,
2:399-403.
9-11
-------
Rogers, C.S. 1990. Responses of coral reefs and reef organisms to sedimentation. Mar. Ecol.
Prog. Ser. 62:185-202.
Rogers, C.S., T. Suchanek, and F. Pecora. 1982. Effects of Hurricanes David and Frederic
(1979) on shallow Acropora palmata reef communities: St. Croix, U.S. Virgin Islands. Bull.
Mar. Sci. 32:532-548.
Rogers, C.S., M. Gilnack, and C. Fitz ID. 1983. Monitoring of coral reefs with linear transects:
A study of storm damage. J. Exp. Mar. Biol. Ecol. 66:285-300.
Rose, C.S., and M.J. Risk. 1985. Increase in Cliona delitrix infestation of Montastrea
cavernosa heads on an organically polluted portion of the Grand Cayman fringing reef.
P.S.Z.N.I.: Mar. Ecol. 6:345-363.
Sammarco, P.W. 1980. Diadema and its relationship to coral spat mortality: grazing,
competition, and biological disturbance. J. Exp. Mar. Biol. Ecol. 45:245-272.
Schmitz, W.J., and W.S. Richardson. 1968. On the transport of the Florida Current. Deep-Sea
Res. 15: 679-693.
Schureman, P. 1958. Manual of harmonic analysis and prediction of tides. U.S. Dept. of
Commerce, Coast, and Geodetic Survey. Special Publication No. 98.
Sedwick, E. 1974. Hydraulic constants and stability criterion for MOB inlet. Thesis. Coastal and
Ocean. Eng. Dept., Univ. of FL. Publ. 74/018.
Sedwick, E.A., and A. J. Mehta. 1974. Data from hydrography study at MOB inlet. Coastal and
Ocean. Eng. Dept., Univ. of FL. Publ. 74/014.
SFWMD. 1988. SWIM plan for Biscayne Bay. South Florida Water Management District, West
Palm Beach, Florida.
Shinn, E.A., and R.I. Wicklund. 1989. Artificial reef observations from a manned submersible
off southeast Florida. Bull Mar. Sci 44:1041-1050.
Simkiss, K. 1964. Phosphates as crystal poisons of calcification. Biol. Rev. 39:487-505
Simkiss, K. 1969. Possible effects of zooxanthellae on coral growth. Experientia 20:140.
Sindermann, C.J. 1976. Effects of coastal pollution on fish and fisheries—With particular
reference to the Middle Atlantic bight. Am. Soc. Limnol. Oceanogr., Spec. Symp. 2, 281-301.
Sindermann, C.J. 1990. Principal diseases of marine fish and shellfish. Vol. 1, 2d ed. Academic
Press, San Diego.
9-12
-------
Skinner, R.H. 1982. The interrelation of water quality, gill parasites and gill pathology of some
fishes from South Biscayne Bay, Florida. Fish. Bull. 80: 269-280.
Smith, J.A., B.D. Zetler, and S. Broida. 1969. Tidal modulation of the Florida Current surface
flow. Marine Tech. Soc. 3: 41-46.
Solbakken, J.E., A.H. Knap, T.D. Sleeter, C.E. Searle, and K.H. Palmork. 1984. Investigation
into the fate of 14C-labelled xenobiotics (naphthalene, phenanthrene, 2, 4, 5, 21, 41, 51-
hexachlorobiphenyl, octachlorostyrene) in Bermudian corals. Mar. Ecol. Prog. Ser. 16: 149-154.
South Florida Regional Planning Council. 1991. Regional Plan for South Florida. Hollywood,
Florida.
South Florida Regional Planning Council. 1992. Compilation of the Spring 1991 Florida Census
Estimating Conference, Population and Demographic Forecast. Hollywood, Florida.
Spies, R. 1984. Benthic-pelagic coupling in sewage-affected marine ecosystems. Mar. Environ.
Res. 13:195-230.
Stambler, N., N. Popper, Z. Dubinsky, and J. Stimson. 1991. Effects of nutrient enrichment and
water movement on the coral Pocillopora damicornis. Pacif. Sci. 45:299-307.
Stommel, H.M. 1965. The Gulf Stream. University of California Press.
Tchernia, P. 1980. Descriptive regional oceanography. Pergamon Press, Paris, France.
Te, F.T. 1991. Effects of two petroleum products on Pocillopora damicornis planulae. Pacif.
Sci. 45: 290-298.
Tetra Tech. 1983. Ecological impacts of sewage discharges on coral reef communities.
Prepared for U.S. Environmental Protection Agency, Office of Water Program Operations,
Washington, DC, by Tetra Tech, Inc., Bellevue, WA.
Thorhaug, A. 1980. Environmental management of a highly impacted, urbanized tropical
estuary: Rehabilitation and restoration. Helgol. Meeresunters. 33:614-623.
Thorhaug, A. 1981. Biology and management of seagrass in the Caribbean. Ambio 10:295-
298.
Thorhaug, A. 1988. Dispersed oil effects on mangroves, seagrasses, and corals in the wider
Caribbean. Proc. Sixth Intern. Coral Reef Symp., Townsville, Australia 2: 337-339.
9-13
-------
Tilmant, J.T. 1987. Impacts of recreational activities on coral reefs. In Human impacts on coral
reefs: Facts and recommendations, ed. B. Salvat, pp. 195-214. Antenne de Tahiti Musum
E.P.H.E., Papetoai, Moorea, French Polynesia.
Tomascik, T. 1991. Settlement patterns of Caribbean scleractinian corals on artificial substrata
along a eutrophication gradient, Barbados, West Indies. Mar. Ecol. Prog. Ser. 77:261-269.
USEPA. 1980. Ocean discharge criteria, final rule. Fed. Reg., Vol. 45, No. 194, 65942-65954.
USEPA. 1982. Revised section 301(h) technical support document. U.S. Environmental
Protection Agency, Office of Water Program Operations, Washington, DC. EPA430/9-82-011.
USEPA. 1988. Used Oil Recycling. U.S. Environmental Protection Agency, Office of Water,
Washington, DC. EPA/530-SW-89-006.
USEPA. 1991. Technical support document for water quality-based toxics control. U.S.
Environmental Protection Agency, Office of Water, Washington, DC. EPA/505/2-90-001.
Vicente, V.P., and J.A. Rivera. 1982. Depth limits of the seagrass Thalassia testudinum (Konig)
in Jobos and Guayanilla bays, Puerto Rico. Carib. J. Sci. 17:73-79.
Von Arx, W.S., D.F. Bumpus, and W.S. Richardson. 1955. On the fine structure of the Gulf
Stream front. Deep-Sea Res. 3: 46-65.
Walsh, G.E., R. Barrett, G.H. Cook, and T.A. Hollister. 1973. Effects of herbicides on seedlings
of the red mangrove, Rhizophora mangle L. Bioscience 23:361-364.
Webster, F.A. 1961. A description of Gulf Stream meanders off Onslow Bay. Deep-Sea Res. 8:
130-143.
Williams, E.H., Jr., and L. Bunkley-Williams. 1990. The world-wide coral reef bleaching cycle
and related sources of coral mortality. Atoll Res. Bull. 335: 1-71.
Williams, S.L. 1987. Competition between the seagrasses Thalassia testudinum and Syringodium
filiforme in a Caribbean lagoon. Mar. Ecol. Prog. Ser. 35:91-98.
Williams, S.L. 1988a. Disturbance and recovery of a deep-water Caribbean seagrass bed. Mar.
Ecol. Prog. Ser. 42:3-71.
Williams, S.L. 1988b. Thalassia testudinum productivity and grazing by green turtles in a
highly disturbed seagrass bed. Mar. Biol. 98:447-455.
Williams, S.L. 1990. Experimental studies of Caribbean seagrass bed development. Ecol.
Monoer. 60:449-469.
9-14
-------
Young, D.R., D.J. McDermott, and T.C. Heesen. 1976. DDT in sediments and organisms around
southern California outfalls. J. Wat Poll. Control Fed. 48(8): 1919-1928.
Young, D.R., M.D. Moore, G.V. Alexander, T-K. Jan, D. McDermott-Erhlich, R.P. Eganhouse,
and P. Hershelman. 1978. Trace elements in seafood organisms around southern California
municipal wastewater outfalls. SCCWRP, El Segundo, CA. Publ. No. 60.
Young, P.H. 1964. Some effects of sewer effluent on marine life. Calif. Fish Game 50:33-41.
Zantopp, R.J., K.D. Leaman, and T.N. Lee. 1987. Florida Current meanders: A close look in
June-July 1984. Phys. Ocean. 17 (5):584-595.
Zetler, B.D. 1968. Preliminary report. Tides in the Gulf of Mexico. National Oceanic and
Atmospheric Administration, Physical Oceanography Laboratory, Miami, Florida. Preliminary
report.
Zieman, J.C. 1975. Tropical sea grass ecosystems and pollution. In Tropical marine pollution,
ed. E.J.F. Wood and R.E. Johannes, pp. 63-74. Elsevier, NY.
Zieman, J.C. 1982. The ecology of the seagrasses of south Florida: A community profile. U.S.
Fish and Wildlife Service, Office of Biological Services, Washington, DC. FWS/OBS-82/25.
Zucca, C.P. 1982. The effects of road construction on a mangrove ecosystem. Trop. Ecol.
23:105-124.
9-15
-------
Appendix A
SEFLOE SAMPLING STATION POSITIONS
-------
.210* W 170- 150- ISC
150* 160* i to* ISC i?o* :co* '".o*
i —; 1—
son>io' so 01.# SO^l.t'
Sampling station positions (01/13/88) for Delray Beach SEFLOE study.
A-l
-------
Sampling station positions (01/12/88) for Boca Raton SEFLOE study.
A-2
-------
Sampling station positions (10/08/87) for Broward County SEFLOE study.
A-3
-------
OKjtnj' 1 ottfoi.i
mVj'J
J
• ¦ j
*141 —
hVj-
Sampling station positions (01/11/88) for Broward County SEFLOE study.
A-4
-------
Z6°01.5' —
26°01.«'—
26°01.3' —
zsooi.a1—
!6®01.1' -
1£°01.0'
I
r«o-r/
::rfx
33«a5.4' 80°05.3'
Sampling station positions
30°05.2* 1 30o05.I' 1 S0°05.3' '
(06/06/88) for Hollywood SEFLOE study.
-------
-------
Sampling station positions (10/18/87) for Miami-Dade North District SEFLOE
study.
A-7
-------
80*03.0' 3 0*04.9'
Sampling station positions (10/20/87) for Miami-Dade North District SEFLOE
study.
A-8
-------
i~ 350' q. .0' »•
—r2- rr1" t ^—
•o"o3.«' to'ot.i' tc'oiz' aoljs.r aootcf
Sampling station positions (06/10/88) for Miami-Dade North District SEFLOE
study.
A-9
-------
TT"
:a- , : r T 1^-
90*0«1' 30*045# 80*04.4' ; 80*04.3' 1 80*1
Sampling station positions (10/27/87) for Miami-Dade Central District SEFLOE
study.
A-10
-------
0-
.1
10 00
90*04. • 80*04. t
2**4.?—
25"44.*-t
j
4
Z3S4A2-
Sampling station positions (01/24/88) for Miami-Dade Central District SEFLOE
study.
A-ll
-------
Appendix B
NPDES PERMIT LIMITS AND MONITORING DATA
-------
NPDES PERMIT UMITS AND MONITORING DATA FOR DELRAY BEACH POTW
FL0035980
FLOW
BOD
5-DAY
BOD
5-OAY
LOADING
TSS
TSS
LOADING
FECAL
COUFORM
PH
TOTAL
RESIDUAL
CHLORINE
MOD
MG/L
LBS/D
MG/L
LBS/D
4/100 ML
S.U.
MG/L
AVQ
HIGH
MONTHLY
AVQ
WEEKLY
AVG
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVG
WEEKLY
AVQ
MONTHLY WEEKLY
AVG AVQ
MONTHLY
AVQ
WEEKLY
AVQ
RANGE
DAILY
MAX
PERMIT
UMITS
REPORT
30.0
45 0
6005 0
9007.0
30 0
45 0
6005 0 9007.0
200.0
6 0-65
REPORT
MONITORING
DATA
07/90
13.28
15.02
7.0
9.0
799 0
1030.0
70
10.0
799 0 1230 0
73.0
245 0
6 7-72
1 60
08/90
14.13
14 76
7.0
80
842 0
975 0
7.0
80
779 0 9410
80
1820
67-72
1 50
09/90
13 73
13.93
70
90
832 0
991 0
7.0
8 0
774 0 9310
61 0
3120
6.8 - 7.1
1 30
10/90
14.17
14.87
BO
100
972 0
11920
70
11.0
791 0 1374 0
79 0
1890
6 8-72
1 30
11/90
14 40
14.65
90
10.0
10190
1233 0
60
80
732 0 967.0
79 0
2480
68-73
3 40
12/90
14.46
15.30
11-0
130
1267 0
1513.0
11.0
16.0
1300 0 1 953 0
93 0
1980
65-75
1 40
01/91
16 18
IB.17
11 0
14 0
1490 0
1920 0
170
30 0
2250 0 4018 0
1040
1840 0
66-72
2 80
02/91
16.13
16 48
20
27.0
N/A
N/A
21.0
26 0
2B69 0 3436 0
1130
186 0
6 6-72
5 00
03/91
15.73
16 05
21.0
24 0
2697 0
3062.0
160
22 0
2413 0 2966 0
121.0
1870
6 5 - 7.6
2 80
04/91
15.12
15 80
22.0
26 0
2734.0
3192.0
20 0
23.0
2541 0 2789 0
1290
206 0
62-72
2 70
05/91
14 00
15.26
11.5
16 5
1355 0
19190
13.0
20 0
1522 0 2303 0
1390
540 0
6.3 - 7 1
2 40
06/91
14.49
16.00
6.1
7.1
681.0
668.0
7.0
10.0
8000 11130
141.0
1680
66-69
1 20
07/91
13.03
13.54
80
100
848 0
1092.0
80
100
B480 1011 0
1450
161 0
63-7.2
4 15
YEARLY
AVERAGE
14 5
100
11966
11 5
14 16 8
100 4
/ 4
-------
NPDES PERMIT LIMITS AND MONITORING DATA FOR BOCA RATON POTW
FL0028344
FLOW
BOO
BOO
TSS
TSS
FECAL
pH
TOTAL
5- DAY
5—DAY
LOADING
CGLIFORM
RBIDUAL
LOADING
CHLORNE
MGD
MG/L
LB/D
MGA.
LB/D
#/100 ML
8 U.
MG/L
AVG HIGH
MONTHLY WEEKLY
MONTHLY WEEKLY
MONTHLY WEEKLY
MONTHLY WEEKLY
MONTHLY WEEKLY
RANGE
MONTHLY WEEKLY
AVG AVG
AVG AVG
AVG AVG
AVG AVG
AVG AVG
AVG AVG
PERMIT
REPOHT
30 0 45 0
30 0 45 0
200 0
8.0- 8 5
REPORT REPORT
LIMITS
MONITORING
DATA
07/00
11 420 12 096
48 87
437.4 874 8
40 40
380 4 402 9
3 0 384 0
63-82
10 10
06/90
11 397 11 456
6 0 7.8
587 9 724 9
4.0 5 0
378 8 478 9
30 20
83- 70
10 10
09/90
10 975 10 979
70 9.1
839 7 831 9
50 80
456 9 548 5
30 50
8 4-70
10 10
10/90
11 596 11 781
5 4 8 4
521 5 628 8
50 70
482 9 685 5
3 0 10
62-72
09 09
11/90
11 375 11.406
5.9 6 7
558 8 838 3
5 0 5 0
473 8 474 8
30 60
82-89
10 10
12/90
11718 12.191
9.0 11.0
8782 1118 7
50 50
487 8 507 6
30 30
6 3-70
0 8 0 8
01/91
12 389 12 893
15 0 20 0
1547 4 2113 9
50 80
5158 6342
30 40
6 1-71
08 08
02/91
12 519 12 696
102 107
1063 3 1131 4
60 70
825 5 740 2
20 60
6 3-70
0 8 0 8
03/9!
12 301 12 872
120 184
1229 2 1 972 2
40 50
409 7 535 9
2 0 38 0
60-7 1
0 8 08
04/Q1
12 500 12 736
5 7 7 0
583 3 742 4
50 70
520 4 742 4
20 10
80-72
09 08
03/91
11 554 1 2 100
8 0 11.0
789 7 1106 6
50 70
481 1 705 5
1 0 2.0
6 4—87
08 09
06/91
12 082 12.596
7.0 9.0
704 2 944 0
40 60
402 4 524 4
1.0 10
83- 69
08 08
07/91
11 848 1 2 351
8.1 11.3
799 1 1162.2
40 70
3948 7199
1 0 2040 0
8 3-83
08 08
YEARLY
AVERAGE
11.8
80
793 1
4 7
482 3
2 3
0 9
-------
NPDES PERMIT LIMITS ANO MONITORING DATA FOR BROWAflD COUNTY POTW
FL0031771
FLOW
BOO
5-DAY
BOO
5-DAY
LOADING
TS9
TS9
LOADING
FECAL
COLIFORM
TOTAL
PHOS
TOTAL
NITROGEN
PH
TOTAL
RESIDUAL
CHLORINE
MGO
MG/L
LBS/O
MQ/L
LBSC
#/100ML
MG/L
MG/L
8 U.
MG/L
AVQ
HIGH
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
1/MONTH
1/MONTH
RANGE
DAILY
MAX
PERMIT
LIMITS
REPORT
250
40 0
REPORT
REPORT
300
45 0
REPORT
REPORT
2000
REPORT
REPORT
REPORT
6.0 — 6 5
REPORT
MONITORING
DATA
07/90
61.47
63 96
24 0
27 0
12364 0
130650
60
90
3177 0
4237 0
50
800
N/A
N/A
6.8 - 7 5
N/A
06/90
ai 90
64 10
22.0
.290
111800
156470
100
130
4924 0
64090
50
100
N/A
N/A
69-7.7
N/A
oe/BO
56 81
61 66
26.0
290
12597.0
131800
90
11 0
4293 0
5264 0
5 0
10.0
N/A
N/A
68-74
N/A
10/90
84 63
69 45
280
32 0
15075 0
17604 0
70
100
40150
51900
50
4000
N/A
N/A
67-74
N/A
11/90
56 63
60 04
60
170
3639.0
6361 0
70
9.0
3181 0
4294 0
50
100
N/A
N/A
88-74
N/A
12/90
57 31
60 13
30
40
15470
16550
70
70
32200
36330
40
600
N/A
N/A
67-77
N/A
01/91
63 97
68 78
60
100
3435 0
5623 0
80
100
4453 0
5523 0
4 0
900
N/A
N/A
69-79
N/A
02/91
64.54
66 34
50
70
2566 0
41020
70
80
39390
41830
50
2000 0
N/A
N/A
7 1-79
N/A
03/91
64 06
67 94
60
100
2911 0
5006 0
50
60
2824 0
3651 0
50
600
N/A
N/A
69-76
N/A
04/91
62 36
69 14
50
80
2344.0
3392 0
7.0
70
3464 0
4406 0
4 0
200
N/A
N/A
69-77
N/A
05/91
59 22
69 43
40
SO
21000
2S120
4 0
50
21600
2565 0
40
300
N/A
N/A
70-77
N/A
08/91
71 36
70 66
60
120
4543 0
6967 0
50
70
29820
4928 0
40
100
N/A
N/A
69-78
N/A
07/91
64 25
66 86
110
150
6066 0
7776 0
40
50
2176 0
2535 0
4 0
100
N/A
N/A
7.2 - 7 7
N/A
YEARLY
AVERAGE
62 4
120
6200 7
68
3446 8
4 5
-------
NPDES PERMIT LIMITS AND MONITORING DATA FOR HOLLYWOOD POTW
FL0026255
FLOW
BOO
5-DAY
BOD '
5-DAY
LOADING
TSS
TSS
LOADING
FECAL
COUFORM
TOTAL
PHoa
TOTAL
NITROGEN
pH
TOTAL
RESIDUAL
CHLORINE
MGD
MG/L
LBS/D
MG/L
LBS/D
#/100 ML
MG/L
MG/L
S U
MG/L
AVQ
HIGH
MONTHLY
AVG
WEEKLY
AVG
MONTHLY
AVG
WEEKLY
AVG
MONTHLY
AVG
WEEKLY
AVG
MONTHLY
AVG
WEEKLY
AVQ
MONTHLY WEEKLY
AVG AVG
1/MONTH
1/MONTH
RANGE
DAILY
MAX
PERMIT
LIMIT8
REPORT
30.0
45.0
REPORT
REPORT
30 0
45 0
REPORT
REPORT
200 0
REPORT
REPORT
60-85
REPORT
MONITORING
DATA
07/90
35 3
36 3
150
16 0
4277 0
4453 0
34 0
43 0
9965 0
12056 0
5 0 110
N/A
N/A
60-75
N/A
08/90
35 7
39 1
8.0
100
2274 0
3154 0
17 0
26 0
5138 0
8012 0
4 0 9 0
N/A
N/A
80-70
N/A
09/90
35 0
37 0
70
7 0
1951 0
2048 0
13 0
13 0
3994 0
3707 0
2 0 3 0
N/A
N/A
60-72
N/A
10/90
35 9
39 4
8.0
10 0
2538.0
2950 0
15 0
19 0
4545 0
6338 0
7 0 10 0
N/A
N/A
80-78
N/A
11/90
34.3
35 J
14.0
21 0
4073 0
5995 0
26 0
47 0
6050 0
13453 0
13 0 24 0
N/A
N/A
53-72
N/A
12/90
33 5
34 4
16 0
20.0
5165 0
5729 0
15 0
19 0
4236 0
5267 0
2 0 4 0
N/A
N/A
59-73
N/A
01/91
36.1
41 1
120
13 0
3982 0
3967 0
13 0
16 0
4238 0
5507 0
5 0 21 0
N/A
N/A
59 -65
N/A
02/91
39 1
43 0
11 0
11 0
3465 0
4095 0
15 0
170
4882 0
5327 0
6 0 16 0
N/A
N/A
8 1-69
N/A
03/91
33 5
35 1
10 0
12 0
2752.0
3131 0
130
15 0
3570 0
4400 0
5 0 12 0
N/A
N/A
6 2-67
N/A
04/91
35 6
39 4
100
13 0
31290
3714 0
11 0
13 0
3336 0
4422 0
19 0 28 0
N/A
N/A
6 1-87
N/A
05/91
36 2
40 3
70
7 0
1973 0
2103 0
10 0
120
3111 0
3423 0
11 0 23.0
N/A
N/A
5 3-75
N/A
06/91
42 9
46 1
10 0
14.0
3505 0
4039 0
27 0
44 0
9496 0
15399 0
6 0 15 0
N/A
N/A
5 9-75
N/A
07/91
40 2
44.5
40
9 0
1546 0
2961 0
13 0
15 0
4300 0
4797 0
3 0 4 0
N/A
N/A
4 8-73
N/A
YEARLY
AVERAGE
38 6
10 3
3125 6
17 2
5272 2
8 9
-------
NPOES PERMIT UMTS AND MONITORING DATA FOR MIAMI-DADE NORTH POTW
FL0032162
FLOW
BOO
5-OAY
BGO
5-OAY
LOADING
TSS
TsS
LOADING
FECAL
COUFORM
TOTAL
PHOS
TOTAL
NTTTOQEN
pH
T6TAL
RESOUAL
CHLORINE
MGD
MG/l
LBS/O
MG/l
LBS/O
#/lOO ML
MG/L
MG/l
8.U.
. MG/L
AVQ
HIGH
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
1/MONTH
1 AO NTH
RANGE
MONTHLY WEEKLY
AVQ AVQ
PERMIT
LIMITS
REPORT
300
49 0
REPORT
REPORT
300
45 0
REPORT
REPORT
2000
REPORT
REPORT
6 0-65
REPORT
MONITORING
DATA
07/90
01 42
62 25
00
11.0
6353 0
7245 0
14 0
170
0207.0
11151 0
170
340
N/A
N/A
6 1-64
054
0 56
(W90
93 23
100.40
11 0
12.0
6886.0
9230 0
21 0
290
15703 0
190600
230
400
N/A
N/A
60-66
0 52
053
0090
02 40
09 07
120
120
6801 0
00040
220
290
16866 0
20132 0
70
11 0
N/A
N/A
60-66
055
0 57
10^0
06 46
10&30
120
14 0
0884 0
120310
170
200
13476 0
178020
35 0
830
N/A
N/A
6 1-66
056
062
11/90
87 90
69 14
120
140
6675 0
100800
190
25.0
141520
18863 0
11 0
230
N/A
N/A
62-67
050
064
12/90
60 67
64 94
11 0
120
7391 0
7066.0
21 0
27 0
137B80
17530 0
290
030
N/A
N/A
60-86
055
0 57
01A1
61.78
64 60
130
14 0
0206 0
9868 0
190
230
13185 0
15218 0
260
48 0
N/A
N/A
60-85
0 57
061
02/91
63 86
87 47
21 0
24 0
14753 0
16728 0
28 0
340
19502 0
23352 0
380
500
N/A
N/A
60-68
054
055
03/91
81 36
69 06
230
31 0
16868.0
20406 0
280
31.0
102D5 0
21028 0
140
630
N/A
N/A
62-67
059
064
04/91
86 03
87 48
100
100
66200
7408.0
160
170
11437.0
12070 0
70
100
N/A
N/A
62-87
0 65
070
09/91
63 73
91 27
11.0
14 0
7555 0
106800
120
150
8775 0
112100
60
180
N/A
N/A
62-88
063
0 74
0*91
68 80
94 37
12 0
190
N/A
N/A
160
24 0
N/A
N/A
190
860
1 97
063
63-70
0 57
062
07/91
88 90
91 9B
11 0
14 0
N/A
N/A
160
280
N/A
N/A
150
200
2 65
1240
6 1-67
004
1 00
YEARLY
AVERAGE
666
13 1
0576 5
194 |
141380
19 2
2 1
06
-------
hPOES PERMIT LIMITS AMD MONITORING DATA FOR MIAMI CENTRAL POTW
F10024806
PLOW
BOO
5-OAY
BaO
5-DAY
LOADING
TSS
TS&
LOADING
PSCAL
COLFORM
TOTAL
PH06
TOTAL
NHROGEN
pH
total
RE9JDUAL
CH-ORIME
MGD
MGA
LBS/O
MGA.
LBSjO
#/100 ML
MG1
MCVL
SU.
MOl
AVQ
HK3H
MONTHLY
AVQ
MEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
MONTHLY
AVQ
WEEKLY
AVQ
1/MONTH
1AAONTH
RANGE
DAILY
MAX
PERMIT
UMfTS
REPORT
300
450
REPORT
REPORT
300
450
REPORT
REPORT
200 0
REPORT
REPORT
REPORT
60-85
REPORT
MONITORING
DATA
07/90
t;v 3
1396
180
23.0
186140
237030
100
120
103600
185700
30
400 0
N/A
N/A
81 -69
3 1
06/90
1343
1420
170
100
183060
217170
60
00
0260 0
156020
20
740000
N/A
N/A
00- 70
20
OB/BO
131 0
137 6
200
220
215140
240460
110
140
12400 0
212640
20
8600
N/A
N/A
6 1 - 7.1
20
10»
131.0
142 3
150
150
181000
170680
100
110
112340
174140
20
120.0
N/A
N/A
83-70
20
11^0
124 6
1300
130
180
136400
17367 0
11 0
120
117080
160830
20
240 ¦ '
tVA
N/A
6 1-70
3 1
\2JBQ
1132
1101
170
200
162710
186130
180
260
17382 0
503140
10
21.0
N/A
N/A
8 1-71
35
0t/©1
122 0
129 3
18.0
200
N/A
NfA
220
290
N/A
N/A
20
25.0
427
24 60
60-7 1
35
Q2M\
124 8
130.3
170
21 0
N/A
N/A
21 0
270
N/A
N/A
20
10 0
387
21 00
82-68
25
coei
122 3
1274
180
170
N/A
N/A
15 0
180
N/A
N/A
20
130
304
27 30
8 1-00
35
04«1
1171
110.4
170
180
N/A
N/A
220
280
N/A
N/A
20
81 0
2 74
22 40
63-70
24
o&ei
111 3
1104
180
230
N/A
N/A
100
230
N/A
N/A
30
12600000
230
25 70
63-71
35
oaei
1308
141 8
180
230
n/a
N/A
130
180
N/A
N/A
40
930 0
1 06
1830
6 1-71
35
07/61
1307
136.8
140
160
N/A
N/A
120
200
N/A
N/A
20
200 0
206
1020
8,1 - 7 1
35
YEARLY
AVERAGE
124 7
168
17575 7
148
120663
22
30
228
29
-------
Appendix C
CONTACT LIST FOR SOUTH FLORIDA
WATER QUALITY STUDY
-------
CONTACT LIST FOR SOUTH FLORIDA WATER QUALITY STUDY
Stephen M. Blair
Marine Biologist
Metropolitan Dade County
Environmental Resources Management
111 NW First Street
Miami, FL 33128
(305) 375-3324
Thomas Cavinder
Dave Commons
Richard Dodge
Craig Knimpel
Supervisory Engineer
U.S. Environmental Protection Agency, Region IV
Environmental Services Division
Athens, GA 30613
(404) 546-2490
Broward County Office of Environmental Services
Wastewater Management Division
2401 N. Powerline Road
Pompano Beach, FL 33069
(305) 960-3066
Nova University
8000 Ocean Dr.
Dania, FL 33004
(305) 920-1978
Coastal Planning and Engineering
3200 N. Federal Highway, Suite 123
Boca Raton, FL 33431
(407) 391-8102
Jean Evoy
Bob Fergen
Metro Dade Planning Department
111 N.W. 1st, Suite 1220
Miami, FL 33128
(305) 375-2835
Hazen and Sawyer
Raleigh, NC
(919) 833-7152
C-l
-------
Brian Flynn Metro Dade Department of Environmental Resources Management
111 N.W. 1st., 13th Floor
Miami, FL 33128
(305) 375-3376
Bertha Goldenberg Process Engineer
Miami-Dade Water and Sewer Authority Department
3575 S. Le Jeune Road
Miami, FL 33146
(305) 669-7781
Broward County Office of Natural Resources Protection
500 East Broward Blvd., Suite 104
Fort Lauderdale, FL 33315
(305) 765-5181
Broward County Erosion Prevention District
Broward County Office of Natural Resources Protection
500 East Broward Blvd., Suite 104
Fort Lauderdale, FL 33315
(305) 765-4013
U.S. Army Corps of Engineers
P.O. Box 4970
Jacksonville, FL 32232
(904) 791-1697
U.S. Environmental Protection Agency, Region IV
Permits Division
345 Courtland Street, N.E.
Atlanta, GA 30365
(404) 347-3633
W. Andrew Johnson P.E. Deputy Director
City of Boca Raton
Public Utilities Department
201 W. Palmetto Park Blvd.
Boca Raton, FL 33432
(407) 338-7307
Thomas Lee University of Miami/RSMAS
Rickenbacker Causeway
Miami, FL 33149
(305) 361-4046
C-2
Fran Henderson
Steve Higgins
Ron Hilton/
Davis Schmidt
Marshall Hyatt
-------
William McLeish
National Oceanic and Atmospheric Administration
Environmental Research Laboratories
Ocean Acoustics Division/AOML
4301 Rickenbacker Causeway
Miami, FL 33149
(305) 361-4402
Susan Markley
Metro Dade Department of Environmental Resources Management
111 N.W. 1st, 13th Floor
Miami, FL 33128
(305) 375-3376
Murray Miller
Richard Ogburn
South Florida Water Management District
P.O. Box 24680
West Palm Beach, FL 33416
(407) 686-8800
South Florida Regional Planning Council
3440 Hollywood Blvd., Suite 140
Hollywood, FL 33021
(305) 961-2999
John Proni
National Oceanic and Atmospheric Administration
Environmental Research Laboratories
Ocean Acoustics Division/AOML
4301 Rickenbacker Causeway
Miami, FL 33149
(305) 361-4312
Michael Schmale
Rosenstiel School of Marine and Atmospheric Science
University of Miami
Rickenbacker Causeway
Miami, FL 33149
(305) 361-4140
Peter Schroeder
Biosystems Research
11550 S.W. 108 Ct.
Miami, FL 33176
(305) 238-5509
Alex Stone
Project Reefkeeper/American Littoral Society
16345 West Dixie Highway
Miami, FL 33160
(305) 945-4645
C-3
------- |