United States
Environmental Protection
Agency
Region 4
345 Courtland Street, NE
Atlanta, GA 30365
EPA 904/10-84 128
November 1984
svEPA
Saltwater Wetlands for
Wastewater Management
Environmental Assessment
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o UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
345 COURTLAND STREET
ATLANTA. GEORGIA 30365
DEC 11 1984
TO: ALL INTERESTED AGENCIES, PUBLIC GROUPS AND CITIZENS
Enclosed is a copy of the Saltwater Wetlands for Wastewater
Management Environmental Assessment. This study was conducted
by EPA, Region IV to assess the use of saltwater wetlands for
wastewater management in the Southeastern United States.
The emphasis of the Saltwater Wetlands Assessment is to
provide a description of key saltwater wetland factors,
current disposal practices, disposal options, regulatory
considerations, and areas where additional wetland wastewater
management research is needed.
The enclosed report represents the final document to be
prepared in this study. If you would like to comment on the
Saltwater Wetlands Assessment or would like additional
information, please contact:
Ronald J. Mikulak, Project Officer
NEPA Compliance Section
EPA, Region IV
345 Courtland Street
Atlanta, GA. 30365
Commercial Phone Number: 404-881-3776
FTS Phone Number: 257-3776
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SALTWATER WETLANDS
FOR
WASTEWATER MANAGEMENT
ENVIRONMENTAL ASSESSMENT
-------
SALTWATER WETLANDS
FOR
WASTEWATER MANAGEMENT
ENVIRONMENTAL ASSESSMENT
SEPTEMBER 1984
Prepared by
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV - ATLANTA
With Assistance From
APPLIED BIOLOGY, INC.
GANNETT FLEMING CORDDRY AND CARPENTER, INC.
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EXECUTIVE SUMMARY
Saltwater wetlands have the potential for use as municipal and
seafood processing wastewater-discharge sites. However, the potential
also exists for adversely Impacting these Important natural resources.
The Saltwater Wetlands for Uastewater Management Environmental Assessment
is designed to explore the feasibility of using saltwater wetlands for
municipal and seafood processing wastewater management and to Identify
areas of concern that are important to local, state and federal agencies
in making wastewater management decisions affecting saltwater wetlands in
the southeastern United States. This assessment 1s a companion study to
the previously initiated Freshwater Wetlands for Wastewater Management
Environmental Impact Statement (EIS).
The emphasis of this Saltwater Wetlands Environmental Assessment 1s
to provide a description of key saltwater wetland factors, disposal prac-
tices and options, regulatory considerations for disposal Implementation,
and areas where additional wetland research is needed.
WETLANDS DEFINITION AND INVENTORY
There are various definitions applied to wetlands by federal agen-
cies and the USEPA Region IV states. The U.S. F1sh and Wildlife Service
classification, developed for the National Wetlands Inventory, relies on
vegetation, hydrology and soil Indicators for characterizing wetlands.
It 1s currently the most comprehensive wetland classification system
available. The system addresses different user needs by providing d1f-
11
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ferent levels of detail, offers regional consistency and recognizes
significant ecological differences among wetland types. The FWS classi-
fication 1s gradually being adopted for use by most regulatory agencies.
Mapping efforts In the six Region IV coastal states were Inventoried.
Figures were used to depict the status of the FWS National Wetlands
Inventory as of October 1983.
EXISTING SALTWATER-WETLAND DISCHARGES
An information survey program was conducted to Identify and charac-
terize existing saltwater-wetland discharges in the USEPA Region IV
coastal states. The majority of those responding to the survey indicated
that they discharged into brackish waters, mostly Into tidal creeks.
None stated that they discharged directly onto saltwater wetlands.
During site visits, wastewater discharges into tidal creeks were observed
on several occasions. Marsh vegetation at the mouth of or bordering
these creeks appeared taller and denser at one site but, for the most
part, did not appear to differ from adjacent areas that are less likely
to be influenced by the discharge.
INSTITUTIONAL CONSIDERATIONS
A large part of federal Institutional involvement pertaining to
wastewater discharges in saltwater wetlands stems from the Clean Water
Act. Regulatory programs established through the Act that are admin-
istered by EPA are the National Pollutant Discharge Elimination System
Permit Program, the 201 Construction Grants Program and the Water Quality
111
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Standards Program. The Dredge and Fill Permit Program is administered by
the Corps of Engineers. Two other federal programs, Fish and Wildlife
Coordination (which involves the Fish and Uildlife Service and National
Marine Fisheries Service) and the National Shellfish Sanitation Program
administered by the Public Health Service, involve advisory duties when a
proposed water resource development activity could adversely impact fish,
wildlife or shellfish of a given water body.
State programs or procedures which impact the feasibility of
discharging wastewater to saltwater wetlands are presented. These
programs and procedures include water quality classifications and stan-
dards, discharge permits and methodology for determining wasteload allo-
cations for wetlands, the process for prioritizing projects for 201
Construction Grant Program funding, and various state coastal area mana-
gement and protection plans. Procedural and regulatory variations among
the states when dealing with saltwater wetlands are also addressed.
These differences are significant in permitting activities in saltwater
wetlands within the states and along state boundaries or interstate
waters.
Key institutional issues related to wastewater management in salt-
water wetlands include the following:
. Lack of wetland definition and lack of specifity in defining
state waters and landward extent of classified water areas.
. Inappropriate water quality criteria applied to wetlands.
. Lack of procedures for establishing effluent limits.
iv
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SCIENTIFIC CONSIDERATIONS
Components of saltwater wetland ecosystems Include geomorphology,
vegetation, hydrology, water quality and wildlife. B1ot1c and abiotic
factors operate in dynamic equilibrium and the characteristics, functions
and processes of saltwater wetlands are variable and Interrelated.
Disposal of municipal or seafood-processing wastewater has the potential
of disrupting the Integrity of these wetlands. However, the potential
for positive effects must also be considered.
Five major factors were found to be important when evaluating
wastewater discharge alternatives in saltwater wetlands. These factors
are:
Erosion would be expected to vary with characteristics of the
soil, density of vegetation and effluent rates per unit of marsh
surface area.
Nutrients may affect the marsh vegetation and/or the estuary.
The types or amounts of nutrients entering the marsh would
depend on the characteristics of the effluent, while their path-
ways In the marsh would depend on such factors as sediment
characteristics, uptake rates by vegetation and frequency of
tidal Inundation.
Toxic substances and pathogens entering the marsh will also vary
according to the quality of the effluent. This factor Is par-
ticularly relevant for consideration because of public health
implications.
Vegetation may be affected by several parameters associated with
wastewater disposal Including decreased salinity, continual soil
saturation and nutrient loading. A primary concern is that
shifts in plant species composition or distribution may occur In
the marsh.
Wildlife may be affected 1f shifts 1n the vegetation occur that
alter food availability, nesting sites, cover or similar habitat
parameters. Wildlife could also be affected by toxic substances
introduced with treated effluent. The occurrence of threatened
and endangered animal species 1s another reason for wildlife to
be a factor for consideration.
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ENGINEERING CONSIDERATIONS
The engineering issues associated with discharging municipal and
seafood processing wastewater to a saltwater wetland are related pri-
marily to maintaining wetland function and ecology while promoting
nutrient removal. Key engineering factors discussed include the
following:
. Selection of a suitable saltwater wetland site for wastewater
discharge;
. Development of hydro!ogic and nutrient loading criteria to deter-
mine detention times and discharge schedules;
. Wastewater discharge system design to determine water depths,
back-up systems, disinfection techniques, etc.;
. Construction methods to install equipment without permanently
disturbing the wetland ecosystem;
. Operation and maintenance options to insure that discharge
amounts, discharge frequency and flow paths are maintained after
system start-up;
. Monitoring and compliance issues to include the definition of
monitoring parameters, sampling techniques and monitoring
schedules to meet permit conditions and requirements.
KEY FACTORS
Key scientific and engineering factors for evaluating saltwater
wetlands as potential wastewater disposal sites are geology, hydrology
and water quality. The key institutional factor is regulatory control.
These key factors are:
. Regulatory control refers to permitting (including effluent
limits), enforcement of water quality standards and funding.
Regulatory requirements may promote or restrict the use of salt-
water wetlands for wastewater discharge.
• Hydro!ogical components refer to the effluent volume and rate(s)
of application, as well as to tidal fluctuations, water table
level, seasonal precipitation, runoff and other natural factors.
vi
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• Water qual1 tv components refer to the constituency of the
effluent and to potential changes 1n water quality parameters
following discharge.
. Geological components refer to compostlion of the sediments,
particularly as they relate to porosity (permeability) and move-
ment of water or wastewater into or through the sediments.
AREAS FOR FURTHER STUDY
The use of saltwater wetlands for the management of municipal or
seafood processing wastewater 1s an area 1n which many technical
questions remain unanswered. Areas for further study and some represen-
tative issues are presented.
. Soils/geomorphology; The rate of nutrient uptake by soils and
length of time that pathogens remain viable in sediments are not
quantified.
. Vegetation; Specific effects of freshwater wastewater discharge
on saltwater wetland vegetation and the ability of natural salt
marsh vegetation to remove nutrients are not known.
. Hydrology; Hydrologlc loading rates suitable to saltwater
wetland maintenance and effects of discharges on seasonal
wet/dry cycles are not well understood. The effects of seasonal
and tidal Influences as well as periodic coastal storms on
wetland water quality in wetland wastewater systems are not
known.
. Wildlife; Specific impacts on shellfish and other aquatic and
terrestrial fauna from the discharge of toxins, metals and
pathogens have not been quantified.
. Engineering; Acceptable loading rates, wastewater detention
times, water depths and effects of chlorine or other disinfec-
tants on the wetland food chain and public health require
further study.
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TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY 11
TABLE OF CONTENTS v111
LIST OF TABLES xl
LIST OF FIGURES xlv
1.0 INTRODUCTION 1-1
1.1 Background and Purpose 1-1
1.2 Areas of Special Concern 1-2
1.3 Approach and Objectives 1-3
2.0 WETLANDS DEFINITION AND INVENTORY 2-1
2.1 Wetlands Definition and Classification 2-1
2.1.1 Marine Classification System 2-8
2.1.2 Estuarlne Classification System 2-9
2.1.3 Classification Comparisons 2-10
2.2 Wetland Inventories 1n Region IV 2-10
2.2.1 North Carolina 2-13
2.2.2 South Carolina 2-13
2.2.3 Georgia 2-17
2.2.4 Florida 2-21
2.2.5 Alabama 2-23
2.2.6 Mississippi 2-28
2.3 Summary 2-28
2.4 Literature Cited 2-31
3.0 PROFILE OF EXISTING SALTWATER-WETLAND DISCHARGES 3-1
3.1 North Carolina 3-6
3.2 South Carolina 3-10
3.3 Georgia 3-12
3.4 Florida 3-14
3.5 Alabama 3-14
3.6 Mississippi 3-15
3.7 Summary — —- . 3-17
4.0 INSTITUTIONAL CONSIDERATIONS 4-1
4.1 Federal Programs 4-2
4.1.1 Water Quality Standards Program 4-2
4.1.2 National Pollutant Discharge Elimination
System (NPDES) Permit Program - 4-7
4.1.3 201 Construction Grants Program 4-11
4.1.4 Corps of Engineers Permit Program —— 4-16
4.1.5 Fish and Wildlife Coordination 4-21
4.1.6 National Shellfish Sanitation Program 4-24
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TABLE OF CONTENTS
(continued)
4.2 State Programs 4-26
4.2.1 Alabama 4-26
4.2.2 Florida 4-29
4.2.3 Georgia 4-34
4.2.4 Mississippi 4-36
4.2.5 North Carolina 4-39
4.2.6 South Carolina 4-44
4.3 Major InstUitional Issues 4-48
4.3.1 Need for Clear Direction in Wetlands
Wastewater Management 4-48
4.3.2 Need to Clarify Regulatory Definitions 4-49
4.3.3 Need for Program Specific Guidance 4-51
4.4 Literature Cited 4-57
5.0 SCIENTIFIC CONSIDERATIONS 5-1
5.1 Geomorphology 5-2
5.1.1 Estuaries 5-2
5.1.2 Salt Marsh Ontogeny 5-7
5.1.3 Soils 5-8
5.1.4 Assessment 5-16
5.2 Vegetation 5-20
5.2.1 Marshes 5-21
5.2.2 Mangrove Swamps 5-29
5.2.3 Aquatic Grassbeds 5-31
5.2.4 Intertidal Flats 5-33
5.2.5 Summary 5-33
5.3 Hydrology 5-34
5.3.1 Regional Characterization 5-36
5.3.2 Hydrologlc Budgeting 5-38
5.3.3 Inundation 5-44
5.3.4 Buffering 5-48
5.3.5 Storage 5-48
5.3.6 Hydraulic Loading 5-49
5.3.7 Impacts from Wastewater Effluent
Application 5-49
5.4 Water Quality 5-50
5.4.1 General Water Quality Parameters 5-51
5.4.2 Nutrient Removal and Metal Uptake 5-58
5.4.3 Assessment 5-69
5.5 Wildlife 5-73
5.5.1 Fish and Shellfish 5-76
5.5.2 Birds 5-77
5.5.3 Reptiles and Amphibians 5-82
5.5.4 Mammals 5-83
5.5.5 Threatened and Endangered Wildlife Species - 5-85
5.5.6 Impacts to Wildlife from Wastewater
Application 5-102
ix
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TABLE OF CONTENTS
(continued)
Page
5.6 Scientific Factors Related to Wastewater
Management in Saltwater Wetlands 5-105
5.6.1 Erosion 5-106
5.6.2 Nutrients 5-107
5.6.3 Toxic Substances 5-108
5.6.4 Vegetation 5-108
5.6.5 Wildlife 5-109
5.7 Literature Cited 5-111
6.0 ENGINEERING CONSIDERATIONS 6-1
6.1 Management of Municipal Wastewaters Utilizing
Saltwater Wetlands 6-2
6.1.1 Planning and Preliminary Design 6-10
6.1.2 Design of Municipal Systems 6-20
6.1.3 Installation and Operation-Maintenance-
Repair 6-29
6.1.4 Monitoring 6-33
6.2 Management of Seafood-Processing Wastewaters
Utilizing Saltwater Wetlands 6-35
6.2.1 Planning and Preliminary Design 6-36
6.2.2 Design and Installation 6-48
6.2.3 Operation, Maintenance, Repair and
Monitoring 6-52
6.3 Engineering-Related Issues and Options — 6-52
6.4 Literature Cited 6-56
7.0 SUMMARY OF INSTITUTIONAL, SCIENTIFIC AND ENGINEERING
CONSIDERATIONS 7-1
7.1 Institutional Considerations 7-1
7.1.1 Federal Involvement — 7-1
7.1.2 State Involvement 7-3
7.2 Scientific Considerations 7-6
7.3 Engineering Considerations 7-7
7.4 Key Factors 7-7
7.5 Study Recommendations —— 7-11
7.5.1 Soils/Geomorphology 7-12
7.5.2 Vegetation 7-12
7.5.3 Hydrology 7-12
7.5.4 Water Quality 7-13
7.5.5 Wildlife 7-13
7.5.6 Engineering 7-13
8.0 LIST OF PREPARERS 8-1
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LIST OF TABLES
Page
Table 2.1-1 Marine and Estuarine Systems with Classes,
Subclasses, and Selected Dominance Types 2-3
Table 2.1-2 A Comparison of the Wetland Classification
Systems Presented in the U.S. Fish and
Wildlife Service Circular A39 and the
U.S. Fish and Wildlife Service Classification
of Wetlands and Deepwater Habitats 2-11
Table 2.2-1 Wetland Inventories in North Carolina 2-14
Table 2.2-2 Wetland Inventories in South Carolina 2-16
Table 2.2-3 Wetland Inventories in Georgia 2-19
Table 2.2-4 Wetland Inventories in Florida 2-22
Table 2.2-5 Wetland Inventories in Alabama 2-25
Table 2.2-6 Wetland Inventories in Mississippi 2-29
Table 3.0-1 U.S. Environmental Protection Agency,
Region IV, Saltwater Wetlands for
Wastewater Management EIA, Wetlands
Discharge Survey 3-2
Table 3.0-2 Number of Saltwater-Wetland Discharges
Surveyed by State and the Number of
Respondents 3-5
Table 3.1-1 Profile of Saltwater Wetland Discharges in
USEPA Region IV Based on Survey Responses 3-8
Table 4.1-1 Agencies and Water Use Classifications for
EPA Region IV Coastal States 4-6
Table 4.1-2 Corps'of Engineers Permit Evaluation
Criteria r— 4-18
Table 4.1-3 Summary of EPA Criteria for Approval of
Dredged or Fill Material Discharge Under
Section 404{b)(l) of the CWA - 4-20
Table 4.1-4 National Marine Fisheries Service
Guidelines for Assessing Wetland
Alteration 4-23
Table 5.1-1 Relative Mobilities of Selected Metals
in Aquatic Systems 5-17
xi
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Table 5.5-1
Table 5.5-2
Table 5.5-3
Table 5.5-4
Table 5.5-5
Table 5.5-6
Table 6.1-1
Table 6.1-2
Table 6.1-3
Table 6.1-4
Table 6.1-5
Table 6.1-6
Table 6.1-7
Table 6.1-8
Table 6.1-9
Table 6.2-1
LIST OF TABLES
(continued)
North Carolina's Protected Species
Associated with Saltwater Wetlands
South Carolina's Protected Species
Associated with Saltwater Wetlands
Page
5-89
5-90
Georgia's Protected Species
Associated with Saltwater Wetlands ................. 5-93
Florida's Protected Species
Associated with Saltwater Wetlands ----------------- 5-94
Alabama's Protected Species
Associated with Saltwater Wetlands ----------------- 5-99
Mississippi's Protected Species
Associated with Saltwater Wetlands
Quality Guidelines, Marine Water Quality and
Typical Effluent Quality for Selected
Constltents
Projected Effluent Quality for Ocean Discharge
and Approximate Marine Water Quality
Potential Impacts of Wastewater on
Wetland Ecosystems
Potential Adverse Effects of Certain Wastewater
Constituents
Physical and Chemical Pollutant Removal
Mechanisms 1n Wetland and Aquatic Systems
5-101
6-3
6-4
6-7
6-8
6-15
Collection of Site-Specific Data for Evaluation
of a Wetland for Wastewater Treatment -------------- 6-18
Effluent Application Configurations
Summary of Example Wastewater Disposal
Capital Costs ------------ —
Design Guide and Checklist for Wetland-
Wastewater Systems ———————
Characteristics of Various Types of Seafood
Processing --------- ..——.— ----- - — -
6-22
6-25
6-30
6-40
xll
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Table 6.2-2
Table 6.2-3
Table 6.2-4
Table 6.2-5
Table 6.3-1
Table 7.3-1
Table 7.3-2
LIST UF TABLES
(continued)
Analysis of Selected Packing House and
Processing Plant Effluents in the Vicinity of
Brunswick, GA During July-August 1979
Descriptions of Physical-Chemical Treatment
Processes Utilized to Treat Seafood Processing
Wastewaters
Technology Assessment for the Seafood Processing
Industry in the Contiguous U.S.
Design Parameters for Types of Seafood Processing
Wastewater Treatment
Engineering-Related Issues and Options
for Saltwater Wetlands
Engineering Factors Pertinent to
Utilizing Wetlands for Any Type
of Wastewater Management
Engineering Factors Pertinent to Utilizing
Wetlands for Seafood-Processing Wastewater
Management
Page
6-43
6-46
6-47
6-50
6-54
7-8
7-10
xiii
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LIST OF FIGURES
Page
Figure 2.2-1 Hierarchial Classification of Wetlands
and Deepwater Habitats of the Marine
and Estuarine Systems 2-5
Figure 2.1-2 Diagrammatic Description of the Marine
System habitats 2-6
Figure 2.1-3 Diagrammatic Description of the Estuarine
system habitats 2-7
Figure 2.2-1 Status of the National Wetlands Inventory
in North Carolina 2-15
Figure 2.2-2 Status of the National Wetlands Inventory
in South Carolina 2-18
Figure 2.2-3 Status of the National Wetlands Inventory
in Georgia 2-20
Figure 2.2-4 Status of the National Wetlands Inventory
in Florida 2-24
Figure 2.2-5 Status of the National Wetlands Inventory
in Alabama 2-27
Figure 2.2-6 Status of the National Wetlands Inventory
in Mississippi 2-30
Figure 5.1-1 Development Stages in a Shoreline of
Submergence 5-3
Figure 5.1-2 Generalized Well-Developed Estuarine System 5-4
Figure 5.1-3 Schematic Representation of Estuarine
Dynamics Showing River Flow Moving Obliquely
Towards the Viewer, Tidal Inlet Flow Moving
Obliquely away from the Viewer During Flood
Tide, and Lateral Distribution Processes
Acting to Disperse Sediment Throughout the
Basin 5-5
Figure 5.1-4 Development of a Typical New England Salt
Marsh with Rising Sea Level and Continued
Sedimentation 5-9
Figure 5.1-5 A Model of the Marsh Nitrogen (N) Cycle
Showing the Major Stores of N and
Interrelated Processes 5-11
Figure 5.1-6 Phosphorus Cycle 1n a Salt Marsh 5-12
xiv
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Figure 5.3-1
Figure 5.3-2
Figure 5.5-1
Figure 5.5-2
Figure 5.5-3
Figure 6.2-1
Figure 6.2-2
LIST OF FIGURES
(continued)
Page
Coastal Energy Levels 5-37
Wetland Water Movement during Tidal Cycle -
The Estuarine Ecosystem of Coastal Alabama
and Representative Energy Symbols —
Common Food Relationships
Generalized Trophic Relationships of
Representative Birds of Estuarine Emergent
Wetlands
Typical Steps Involved in Preparing Seafood
for Market
Typical Shrimp Processing Schematic
5-47
5-75
5-78
5-80
6-37
6-39
xv
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1.0 INTRODUCTION
Saltwater wetlands have the potential for use as
wastewater-dlsposal sites. However, the potential
also exists for adversely Impacting these Important
natural resources. This assessment 1s designed to
explore the feasibility and acceptability of using
saltwater wetlands for municipal and seafood pro-
cessing wastewater management and to Identify areas
of concern that are Important to local, state and
federal agencies 1n making wastewater management
decisions affecting saltwater wetlands 1n the
southeastern United States. The emphasis of this
assessment 1s in providing a description of key
saltwater wetland factors, discharge practices and
options, and regulatory considerations for
discharge implementation.
1.1 BACKGROUND AND PURPOSE
The Saltwater Wetlands for Wastewater Management Environmental
Assessment (Saltwater Wetlands Assessment) was Initiated in response to
inquiries and concerns expressed by agencies, states and Individuals who
were aware of the potential for wastewater management 1n saltwater
wetlands and who requested an examination of the Issue.
Much of the future growth 1n the U.S. 1s projected to occur 1n the
Southeast and will ultimately affect coastal areas. Many small coastal
communities are experiencing or will experience an Increase in wastewater
discharged from municipal treatment plants because of seasonal population
Increases caused by vacationers and/or seafood processing wastewaters
from facilities operating in summer and early fall. The growth of small
coastal communities 1s likely to result in the loss of biologically pro-
ductive and commercially valuable saltwater wetlands. The use of these
wetlands for wastewater management, when adverse Impacts can be avoided
1-1
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or minimized, could allow for the alleviation of the potential problem of
insufficient suitable wastewater discharge sites and use of wetlands in
such a way that they will be preserved. However, care must be exercised
to assure that the use and function of these wetlands are not impacted by
wastewater discharges.
The purpose of the Saltwater Wetlands Environmental Assessment is,
thus, to examine the institutional, scientific and engineering issues
that are important in considering the use of saltwater wetlands in the
southeastern U.S. for the disposal of treated municipal wastewater and
seafood-processing wastewater and to identify areas for further study.
This is a generic study that includes the U.S. Environmental
Protection Agency (EPA) Region IV's six coastal states: North Carolina,
South Carolina, Georgia, Florida, Alabama and Mississippi. The present
assessment is a companion study to the previously initiated Freshwater
Wetlands for Wastewater Management EIS.
1.2 AREAS OF SPECIAL CONCERN
The use of saltwater wetlands to receive treated wastewater may pro-
vide a discharge alternative that could offer significant environmental
advantages, including discharge options in areas that lack a suitable
receiving stream and wetland preservation. Many questions, however,
arise when the potential impacts of wetland discharges are considered.
Areas of special concern include:
1-2
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The quality and quantity of effluent entering wetlands,
Specific effluent characteristics or other circumstances which
would preclude the discharge of wastewater to saltwater
wetlands,
Presence of threatened or endangered species in wetlands,
Impacts of effluent of various qualities and volumes on floral
and faunal communities and species,
Hydrologic consequences of wetland discharges,
Seasonal variations in wetland characteristics,
Maintenance of current water-quality standards and wastewater-
treatment requirements while utilizing wetlands for wastewater
management,
Potential beneficial results of a wetlands discharge, par-
ticularly to artifically depleted wetlands,
Institutional constraints or prohibitions on wetlands discharge
alternatives at federal, state or local levels,
Differentiation of wetland types, identifying those more or less
appropriate for wetlands discharges,
Impacts to recreational or commercial resources,
Impacts to wetland function,
Salinity impacts,
Food chain impacts,
Available analytical monitoring techniques, and
Financial impacts related to use of a wetlands as compared to
other alternative discharges.
1.3 APPROACH AND OBJECTIVES
This report provides an identification of the issues and needs of
current technical and institutional aspects associated with saltwater-
wetland discharges. The emphasis In this effort is in providing a
description of key saltwater wetland factors, disposal practices and
1-3
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options, and federal, state and local implementation practices and
options. Special objectives of this assessment Include:
Inventory and describe existing wetland discharges,
Conduct a regional survey to identify existing technical and
Institutional considerations associated with saltwater-wetland
discharges,
Identify key wastewater parameters and key wetland factors cri-
tical to maintaining beneficial wetland functions and uses,
Identify key Institutional factors to be considered in the regu-
lation of wetlands used for wastewater management, and
Identify technical areas for which additional study is recom-
mended.
1-4
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2.0 WETLANDS DEFINITION AND INVENTORY
There are various definitions applied to wetlands
by federal agencies and the Region IV states.
These definitions are based on soils, hydrology
and/or vegetation. A purpose of this chapter is to
establish the system of definitions used in the
Saltwater Wetlands Environmental Assessment and
correlate this sytem with other existing defini-
tions. Another component of this chapter is an
inventory of currently mapped saltwater wetlands
and the status of such mapping activities.
2.1 WETLANDS DEFINITION AND CLASSIFICATION
Several definitions and classification schemes have been applied to
wetlands. Among the federal agencies, the Corps of Engineers (COE) and
the Fish and Wildlife Service (FWS) have developed comprehensive classi-
fication systems, with that recently developed by the FWS being the most
comprehensive to date. The FWS wetland classification system was deve-
loped by Cowardin et al. (1979) for the National Wetlands Inventory. It
provides several different levels of detail in the classification of a
wetland and, therefore, addresses different user needs. This system
relies on vegetation, hydrology and soil Indicators to characterize
wetland types.
The FWS classification system was selected for use in the Freshwater
Wetlands EIS (EPA, 1983) and its use will continue in the Saltwater
Wetlands Assessment. The FWS system was chosen because of Its regional
consistency and because it recognized significant ecological differences
among wetland types (EPA, 1983). The FWS classification system is gra-
dually being adopted for use by most regulatory agencies, which further
supports its use in the present assessment.
2-1
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The FMS classification was Intended 1) to define ecological units
having certain natural attributes 1n common; 2) to arrange these units
in a system for the purpose of resource management; 3) to supply units
for wetland Inventory and mapping and 4) to provide consistency 1n con-
cepts and terminology throughout the United States (Cowardln et al.,
1979). These authors defined wetlands as "lands that are transitional
between terrestrial and aquatic systems where the water table 1s usually
at or near the surface or the land 1s covered by shallow water."
The FWS classification system 1s a hlerarchlal series proceeding
from the system level (e.g., marine, riverine) to the subsystem (e.g.,
subtidal), class (e.g., unconsolldated bottom), subclass (e.g., organic)
and dominance type levels (e.g., clam worm, Nereis succlnea). Modifiers
for water regimes (e.g, subtidal), water chemistry types (e.g., mixoha-
line) and soils (e.g., add) are used for class, subclass and dominance
type descriptions. Special modifiers (e.g., partly drained) are also
used to relate manmade alterations In wetlands and deepwater habitats.
Cowardin et al. (1979) have reviewed five systems in the FWS
classification: Marine, Estuarlne, Riverine, Lacustrine and Palustrine.
Only the Marine and Estuarlne Systems are relevant to the Saltwater
Wetlands Assessment (Table 2.1-1; Figures 2.1-1 through 2.1-3). Classes
which may contain elements pertinent to this EIS are indicated by
brackets in Table 2.1-1. The heavy lines used in Figure 2.1-1 show those
classes which are pertinent to this EIS.
2-2
-------
TABLE 2.1-1
MARINE AND ESTUARINE SYSTEMS WITH CLASSES, SUBCLASSES,
AND SELECTED DOMINANCE TYPES (EXCERPTED FROM COWARDIN ET AL., 1979)*
System, Class, and Subclass
Examples of Dominance Types
MARINE
Rock Bottom
Bedrock
Rubble
Unconsolidated Bottom
Cobble-Gravel
Sand
Mud
Organic
[Aquatic Bed
Rooted Vascular
L Algal
Reef
Coral
Worm
Rocky Shore
Bedrock
.Rubble
Unconsolidated Shore
Cobble-Gravel
Sand
Mud
_ Organic
ESTUARINE
Rock Bottom
Bedrock
Rubble
Unconsolldated Bottom
Cobble-Gravel
Sand
Mud
_ Organic
Aquatic bed
Algal
Rooted Vascular
. Floating
Reef
Mollusk
Worm
American lobster (Hqmarus americanus)
Encrusting sponge (Hippospongia gossyplna)
Brittle star (Arophipholis squamata)
Great Alaskan tell in (TeTlina lutea)
Atlantic deep-sea scallop (PTacopecten
maqellanicus)
Clam worm (Nereis succlnea)
Turtle grass (Thalassia testudinum)
Kelp (Macrocystls pyrlferal
Coral (Porltes porltes)
Reef worm (Sabellaria cementarium)
Gooseneck barnacle (Pollicipes polymerus)
California mussel (Mytllus californianus)
Acorn barnacle (Balanus balanoides)
P1smo clam (Tlvela stultorum)
Boring clam (Platyodon cancellatus)
False angel wing (Petrlcola pholadifornris)
Sea whip (Muricea callfornlca)
Tunicate (Cnemldocarpa f.1_n_marjcjensis_)
Smooth Washington clam (Saxidomus giganteus)
Sand dollar (Dendraster excentricus)
Baltic macoma""ffiacoma balthlca)
Soft-shell clam (Mya~arenaria)
Rockweed (Fucus veslculosus)
Eel grass (ZosterlTmarlna)
Water hyacinth (Eichhornia crassipes)
Eastern oyster (Crassostrea v1rg1n1ca)
Reef worm (SabellaHa florldensis)
2-3
-------
TABLE 2.1-1
(continued)
MARINE AND ESTUARINE SYSTEMS WITH CLASSES, SUBCLASSES,
AND SELECTED DOMINANCE TYPES (EXCERPTED FROM COWARDIN ET AL., 1979)*
System, Class, and Subclass
Examples of Dominance Types
Streambed
Cobble-Gravel
Sand
Mud
Organic
Rocky Shore
Bedrock
.Rubble
Unconsolidated Shore
Cobble-Gravel
Sand
Mud
-Organic
Emergent Wetland
Persistent
. Nonparsistent
"Scrub-Shrub Wetland
Needle-leaved Evergreen
Broad-leaved Evergreen
Needle-leaved Deciduous
Broad-leaved Deciduous
-Dead
"Forested Wetland
Needle-leaved Evergreen
Broad-leaved Evergreen
Needle-leaved Deciduous
Broad-leaved Deciduous
.Dead
Blue mussel (Mytilus eduHs)
Red ghost shrimp (Callianassa
californiensis)
Mud snail (Nassarlus obsoletus)
Ribbed mussel (Modiolus demissus)
Acorn barnacle (Chthamalus fragills)
Plate limpet (Acmaea testudinails)
Blue mussel (Mytilus edulls)
Quahog (Mercenaria mercenaria)
Clam worm (Nereis succlnea)
Fiddler crab (Uca pugnax)
Saltmarsh cordgrass (Spartina alternlflora)
Samphire (Sallcornia europea)'
Sitka spruce (Picea sitchensis)
Mangrove (Conocarpus erectusT"
Bald cypress (TaxgdlunTaTsTTchum)
Marsh elder (Iva frutescens)
None
Sitka spruce (Picea sitchensis)
Red mangrove (Rhizophora mangle)
Bald cypress (Taxodium distlchum)
Red ash (Fraxinus pennsylvamca)
None
*The Riverine, Lacustrine and Palustrine Systems have been deleted. Classes
which may be pertinent to this study are indicated by brackets.
2-4
-------
SYSTEM
SUBSYSTEM
CLASS
•MARINE'
'SUBTIDAL-
INTERTIDAL-
'SUBTIDAL'
ESTUARINE-
INTERTIDAL-
- Rock Bottom
- Unconsolidated Bottom
• Aquatic Bed
-Reef
E Aquatic Bed
Reef
Rocky Shore
Unconsolidated Shore
pRock Bottom
^-Unconsolidated Bottom
p*Aquatlc Bed
L-Reef
Aquatic Bed
-Reef
-Stream bed
-Rocky Shore
Unconsolidated Shore
Emergent Wetland
•Scrub-Shrub Wetland
Forested Wetland
Figure 2.1-1.
Hierarchial classification of wetlands and deepwater habitats
of the Marine and Estuarine Systems. (Source: excerpted from
Cowardin, et al., 1979 with the Rlvertine, Lacustrine and
Palustrine Systems deleted, classes pertinent to this study
are highlighted by dark line).
2-5
-------
UPLAND
C
3
Q
^
Seaward Limit of Marine System »-
MARINE
•
f INTERTIDAL ^ . SUBTIDAL ^ INTERTIDAL SUBTIDAL
T3
CD
•»->
(0
-o
•r- (U'—^
i— J_ J=
000
1/1 -C
ITJ
•o
•r- E
r— O
O -P
V) •*->
C O
O QQ
O
C
3
— -*7i
——^— a
a IRREGULARLY
•a
(O
-o
•i-
•M
(O
TO E
•r- O
r— -l->
0 -M
(/) O
C CD
O
O
C
13
^~ -^
FLOODED ^^-^
b REGULARLY FLOODED
OJ
Q.
O
CO
r™
*o
J^%
^*
rt 1
sU
*^™
-LI
^*
o
EHWS
ELWS
\
c IRREGULARLY EXPOSED "X
d SUBTIDAL
Figure 2.1-2.
Diagrammatic description of the Marine System habitats. Note:
"EHWS = extreme high water of spring tides; ELWS = extreme low
water of spring tides." (Source: excerpted from Cowardin, et
al., 1979).
2-6
-------
UPLAND
ESTUARINE
UPLAND
ESTUARINE
INTERTIDAL SUBTIDAL INTERTIDAL
^ ^ .
to
w
Q
W
rj| '""N
Q S C
MOO
i-J E-i P*
O H
CO O H
CJ -H
INTERTIDAL
SUBTIDAL
£ ^
O W J=
M « u
iJ O to
O DC
-------
2.1.1 Marine Classification System
The FWS classification defines the Marine System as "the open ocean
overlying the continental shelf and its associated high energy coastline"
(also see Figure 2.1-2). Habitats in the Marine System are influenced by
open ocean currents and tidal flows and, in an ecological sense, are
related to traditional wetlands because of tidal flow interactions.
Salinities are above 30 parts per thousand (ppt) and generally without
dilution other than some freshwater Influence at the mouths of estuaries
and from rainfall.
The limits of the Marine System are from the edge of the continental
shelf to one of the following:
1. The landward boundary of tidal flooding (extreme high water of
spring tides) including the splash zone from breaking waves;
2. The seaward boundary of wetland emergents, trees or shrubs; or
3. The seaward boundary of the Estuarine System, where this boun-
dary is determined by non-vegetation factors.
The distribution of biota within the Marine System in the
southeastern U.S. is Influenced by wave exposure, substrate texture and
physiochemical composition, tidal amplitude, site latitude relative to
temperature, and solar radiation.
The two subsystems of the Marine System are the subtidal and Inter-
tidal. The subtidal subsystem pertains to substrate that 1s always sub-
merged While the intertidal subsystem refers to substrate that is exposed
and flooded by the tide and includes the shoreline splash zone.
2-8
-------
2.1.2 Estuarlne Classification System
The Estuarlne System "consists of deepwater tidal habitats and adja-
cent tidal wetlands that are usually semi enclosed by land but have open,
partly obstructed, or sporadic access to the open ocean, and in which
ocean water is at least occasionally diluted by freshwater runoff from
the land" (Cowardin et al.,1979; also see Figure 2.1-3). Salinities may
be above open ocean levels periodically because of evaporation, but may
also be diluted along low energy coastlines.
The Estuarine System extends to one of three boundaries:
1. Upstream and landward to where ocean salinities are less than
0.5 ppt during average annual low flow;
2. To an imaginary line drawn to enclose the mouth of a river, bay
or sound; and
3. To the seaward boundary of wetland emergents, shrubs or trees
if not included above in Item 2.
In addition, offshore areas that are "of continuously diluted seawater"
are also part of the Estuarine System.
The Estuarine System is described as a low-energy (wave action)
system that includes both estuaries and lagoons, and is more strongly
affected by land than is the Marine System. Oceanic tides, freshwater
runoff, precipitation, evaporation and wind influence estuarine water
chemistry and water regimes. Salinities are hyperhaline (>40 ppt), euha-
line (30.0-40 ppt) or mixohaline (0.5-30 ppt). The latter includes poly-
haline (18.0-30 ppt), mesohaline (5.0-18 ppt) and oligohaline (0.5-5
ppt). Estuarine salinities can be variable or fairly stable. As in the
2-9
-------
case of the Marine System, the Estuarlne System subsystems are either
subtidal or 1ntert1dal.
2.1.3 Classification Comparisons
Several wetland classification systems devised within the scientific
and regulatory communities are reviewed in the Freshwater Wetlands EIS
(EPA, 1983). The most frequently used wetland classification system in
the U.S. was FWS Circular 139 (Shaw and Fredine, 1956) that replaced an
earlier classification by Martin et al. (1953). Circular #39 delineates
wetlands into 20 different types based on vegetation and hydrology.
Because of the widespread use of Circular #39 since 1956, a significant
amount of state and federal legislation 1s tied to Us definitions and
classification (EPA, 1983). Although the trend is presently toward
adopting the more detailed FWS classification developed for the National
Wetlands Inventory (Cowardin et al., 1979), continued use of Circular #39
warrants a comparison of the two classification systems. Comparisons
relevant to saltwater wetlands are presented in Table 2.1-2.
2.2 WETLAND INVENTORIES IN REGION IV
Coastal wetland classification and mapping projects have been done by
a variety of state and federal agencies. The FWS National Wetlands
Inventory 1s the most comprehensive mapping effort In Region IV, but this
current Inventory has been preceded by other national inventories (EPA,
1983). The figures accompanying each of the following sections
Illustrate the status of the FWS Inventory as of October 1983.
2-10
-------
TABLE 2.1-2
A COMPARISON OF THE WETLAND CLASSIFICATION SYSTEMS PRESENTED IN THE
U.S. FISH AND WILDLIFE SERVICE CIRCULAR #39 AND THE
U.S. FISH AND WILDLIFE SERVICE CLASSIFICATION OF WETLANDS AND DEEPWATER HABITATS
(EXCERPTED FROM COWARDIN ET AL., 1979, INCLUDING REFERENCES:
NON-SALTWATER WETLAND INFORMATION DELETED)
ro
i
Circular #39 type and references
for examples of typical vegetation
Classification of Wetlands and Deepwater Habitats
Classes
Water regimes
Type 12-coastal shallow fresh marshes
Marsh (Anderson et al. 1968) Emergent Wetland
Estuarine bay marshes, estuarine
river marshes (Stewart 1962)
Fresh and intermediate marshes
(Chabreck 1972)
Type 13-Coastal deep fresh marshes
Marsh (Anderson et al. 1968)
Estuarine bay marshes, estuarine
river marshes (Stewart 1962)
Fresh and intermediate marshes
(Chabreck 1972)
Type 14-Coastal open fresh water
Estuarine bays (Stewart 1962)
Aquatic Bed
Unconsolidated
Bottom
Type 15-Coastal salt flats
Panne, slough marsh (Redfield 1972) Unconsolidated
Marsh pans (Pestrong 1965) Shore
Type 16-Coastal salt meadows
Salt marsh (Redfield 1972;
Chapman 1974)
Emergent Wetland
Regularly Flooded
Irregularly Flooded
Semipermanently Flooded-
Tidal
Emergent Wetland Regularly Flooded
Subtidal
Permanently Flooded-
Tidal
Regularly Flooded
Irregularly Flooded
Irregularly Flooded
Salinity
Mixohaline
Fresh
Mi xohali ne
Semipermanently Flooded- Fresh
Tidal
Mixohaline
Fresh
Hyperhaline
Euhaline
Euhaline
Mixohaline
-------
TABLE 2.1-2
(continued)
A COMPARISON OF THE WETLAND CLASSIFICATION SYSTEMS PRESENTED IN THE
U.S. FISH AND WILDLIFE SERVICE CIRCULAR #39 AND THE
U.S. FISH AND WILDLIFE SERVICE CLASSIFICATION OF WETLANDS AND DEEPWATER HABITATS
(EXCERPTED FROM COWARDIN ET AL., 1979, INCLUDING REFERENCES:
NON-SALTWATER WETLAND INFORMATION DELETED)
Classification of Wetlands and Deepwater Habitats
Circular #39 type and references
for examples of typical vegetation
Classes
Water regimes
Salinity
to
I—•
10
Type 17-Irregularly flooded salt
Marshes
Salt marsh (Chapman 1974)
Saline, brackish, and inter-
mediate marsh (Eleuterius 1972)
Type 18-Regularly flooded salt
marshes
Salt marsh (Chapman 1974)
Emergent Wetland Irregularly Flooded
Emergent Wetland Regularly Flooded
Euhaline
Mixohaline
Euhaline
Mixohaline
Type 19-Sounds and bays
Kelp beds, temperate grass flats
(Phillips 1974)
Tropical marine meadows (Odum
1974)
Eel grass beds (Akins and
Jefferson 1973; Eleuterius 1973)
Type 20-Mangrove swamps
Mangrove swamps (Walsh 1974)
Mangrove swamp systems
(Kunezler 1974)
Mangrove (Chapman 1976)
Unconsolidated
Bottom
Aquatic Bed
Flat
Scrub-Shrub
Wetland
Subtidal
Irregularly Exposed
Regularly Flooded
Irregularly Flooded
Irregularly Exposed
Regularly Flooded
Forested Wetland Irregularly Flooded
Euhaline
Mi xohali ne
Hyperhaline
Euhaline
Mixohaline
Fresh
-------
2.2.1 North Carolina
Early coastal-wetlands mapping effort 1n North Carolina was completed
for 41 coastal plain counties 1n 1962 using the wetlands classification
system of FWS Circular #39 (Table 2.2-1). This project was Intended for
wildlife management purposes and produced maps at 1:250,000 scale. In
1976 mapping of 20 coastal counties was performed that described coastal
wetlands in a single tidal-marshland category. Maps at a scale of
1:24,000 were produced.
Smaller mapping projects were undertaken in 1982 including 1:24,000
scale mapping of the peninsula between Pamlico and Albermarle Sounds.
This EPA sponsored mapping was in response to significant agricultural
clearing and development 1n wetland areas. Scattered mapping efforts
(Figure 2.2-1) by the U.S. Fish and Wildlife Service as part of the
National Wetlands Inventory include work in the Currituck Sound area and
work in progress in the Pamlico/Albermarle Peninsula. Much of the FWS
mapping in North Carolina is in the planning stages at this point, but
the entire coastal plain eventually will be mapped as part of the
National Wetlands Inventory.
2.2.2 South Carolina
In 1976 all non-forested tidal wetlands were mapped at 1:24,000 scale
by the South Carolina Wildlife and Marine Resources Department (SCWMRD)
but were never formally published (Table 2.2-2). Maps at scales of
1:24,000 and 1:100,000 have been made for all of the coastal wetlands in
South Carolina by the U.S. Fish and Wildlife Service as part of the
2-13
-------
TABLE 2.2-1
WETLAND INVENTORIES IN NORTH CAROLINA
Inventory coverage
Classification
Scale
Date
Resolution
Agency
Coastal Plains of
N.C. (41 counties)
Vegetational
(FWS Circular
#39)
1:250,000 1962 40 acres
N.C. Office of Coastal
Management
ro
Currituck Sound
(National Wetlands
Inventory)
Hydrology/Soils/ 1:24,000 1982 1 acre
Vegetation
(Cowardin et al.)
to the subclass and
water regime level
U.S. Fish and Wildlife
Service
Peninsula between
Albemarle and Pamlico
Sounds
Vegetational
1:24,000 1982 1 acre
U.S. Environmental
Protection Agency
-------
I
LEGEND
SEPTEMBER 1983
® IN PROGRESS
9 LARGE SCALE DRAFT OVERLAYS OR MAPS AVAILABLE
» LARGE SCALE FINAL OVERLAYS OR MAPS AVAILABLE
• SMALL SCALE AND LARGE SCALE MAPS AVAILABLE
© SMALL SCALE MAPS ONLY
Figure 2.2-1. Status of the National Wetlands Inventory in North Carolina
Source: U.S. Fish and Wildlife Service. October 1983.
-------
TABLE 2.2-2
WETLAND INVENTORIES IN SOUTH CAROLINA
Inventory coverage
Classification
Scale
Date
Resolution
Agency
Wan do River Study
Vegetational
1975
S.Ci Water Resources
Commission
Non-forested tidal
wetlands (not published)
Vegetational
1:24,000 1976 1 acre
S.C. Wildlife and Marine
Resources Department
ro
Santee and Cooper River
Basins
Hydrology/Soils
Vegetation
(Cowardin et al.)
to the subclass
level including
special modifiers
1:24,000 1982 1-3 acres S.C. Wildlife and Marine
Resources Department
Coastal Plains
(National Wetlands
Inventory)
Hydrology/Soils
Vegetation
(Cowardin et al.)
to the class
level only
1:24,000
1:100,000
1982
1 acre
U.S. Fish and Wildlife
Service
-------
National Wetlands Inventory (Figure 2.2-2). A limited mapping project
for the Wando River basin near Charleston was produced in 1975 by the
South Carolina Water Resources Commission. Mapping of the Santee and
Cooper River Basins has been undertaken by SCWMRD with the U.S. Fish and
Wildlife Service. This work is at a scale of 1:24,000 and uses the FWS
classification system of Cowardin et al (1979) with modifications for
added mapping detail.
2.2.3 Georgia
The USDA Soil and Conservation Service developed the first wetland
mapping of the eight coastal Georgia counties 1n 1977 (Table 2.2-3).
Wetland classifications derived from aerial photograph interpretation
were combined with soil and hydrology factors for computerized map pro-
duction. This Map Information and Display System (MIADS) produced maps
at scales of 1:20,000 and 1:24,000. The Department of Natural Resources
Office of Planning and Research prepared statewide land usage and vegeta-
tive cover maps in 1977 based on LANDSAT resources. Bottomland wetlands
are defined in this mapping.
Coastal Georgia has been mapped (Figure 2.2-3) at 1:24,000 and
1:100,000 scales by the U.S. Fish and Wildlife Service as part of the
National Wetlands Inventory. The system of Cowardin et al. (1979) was
used only to the class level for this mapping.
2-17
-------
LEGEND
SEPTEMBER 1983
-------
TABLE 2.2-3
WETLAND INVENTORIES IN GEORGIA
Inventory coverage
Classification
Scale
Date
Resolution
Agency
Coastal wetlands
(eight coastal counties)
Vegetational
community/
hydrology/sol Is
(Martin et al.)
1:20,000 1977 3-10 acres USDA Soil Conservation
1:24,000 Service
Statewide land classi-
fication/vegetative
cover
LANDSAT data
varied
1977
1 acre
Ga. Dept. of Natural
Resources, Office of
Planning & Research
Coastal wetlands
(National Wetlands
Inventory)
Hydrology/Sol Is/
Vegetation
(Cowardin et al.)
classified only
to the class level
1:24,000
1:100,000
1982
1 acre
U.S. Fish and Wildlife
Service
-------
LEGEND
SEPTEMBER 1983
9 IN PROGRESS
9 LARGE SCALE DRAFT OVERLAYS OR MAPS AVAILABLE
» LARGE SCALE FINAL OVERLAYS OR MAPS AVAILABLE
• SMALL SCALE AND LARGE SCALE MAPS AVAILABLE
6 SMALL SCALE MAPS ONLY
Fiaure 2 2-' Status of the National Wetlands Inventory In Georgia.
Source: U.S. Fish and Wildlife Service. October 1983,
2-20
-------
2.2.4 Florida
Various state agencies and the U.S. Fish and Wildlife Service have
produced substantial mapping In south and northwest Florida (Table
2.2-4). Large portions of this work are at a rather small scale
(>1:100,000).
The Kissinvnee-Everglades mapping project 1s concerned with energy
flux and land-use Implications of mapped vegetation communities.
Chronological presentations for circa 1900 (primitive), circa 1953 and
1973 land-use conditions were prepared. Mapping was performed at scales
of 1:250,000 and 1:63,360 with greatest emphasis placed on Lee, Hendry
and Collier Counties within the Kissimmee-Everglades basin.
A survey of forested wetlands was produced 1n 1976 by the University
of Florida Center for Wetlands at a scale of 1:500,000. Several
subclassifications were defined 1n that project but a single forest-
wetlands category was the sole forest vegetation descriptor actually
Included in final mapping. The Northeast Gulf River Basin study prepared
1:24,000 scale mapping of wetlands for regional and local land use
planning. The South Florida Water Management District prepared wetlands
mapping in 1976 based on soil hydrology and vegetation communities for a
number of south Florida counties at scales of 1:500,000 and 1:24,000.
The Center for Wetlands prepared mapping of wetlands in the St. Johns
River Water Management District 1n 1979 at scales of 1:63,360 and
1:253,440.
2-21
-------
TABLE 2.2-4
WETLAND INVENTORIES IN FLORIDA
Inventory coverage
Classification
Scale
Date
Resolution
Agency
ro
ro
Wetlands in the Kissimmee-
Everglades Basin of south
Florida
Coastal Wetlands
Forested wetlands
throughout the state
Northeast Gulf River
Basin
Wetlands in the St. Johns
River Water Management
District
Central and Southern
Florida Flood Control
District
South and Northwest
Florida (National Wet-
lands Inventory)
Vegetationa1
community
(Univ. of Fla.)
Vegetational
community
Vegetational
community/hy-
drology
(Univ. of Fla.)
Vegetational
community/
soils (FDNR)
Vegetational
community
(Univ. of Fla.)
Vegetational
community/
hydrology
Hydrology/Soils/
Vegetation
(Cowardin et al.)
to the subclass
and water regime
level.
1:250,000
1:63,360
1:125,000
1:63,360
1:253,440
1:500,000
1:24.000
1:24,000
1:100,000
1976
1975
1979
1976
1982
10 acres
3 acres
40 acres
1:500,000 1976 10 acres
1:24,000 1976
15 acres
10 acres
2 acres
1 acre
University of Florida
Center for Wetlands
Fla. Dept. of Natural
Resources - Bureau of
Coastal Zone Planning
University of Florida
Center for Wetlands
USDA Soil Conservation
Service
University of Florida
Center for Wetlands
South Florida Water
Management District
U.S. Fish and Wildlife
Service
-------
South and northwest Florida have been mapped extensively by the
U.S. F1sh and Wildlife Service as part of the National Wetlands Inventory
(Figure 2.2-4).
2.2.5 Alabama
The Alabama Marine Environmental Sciences Consortium has conducted
four mapping projects In that state's two coastal counties, Mobile and
Baldwin, with Incentives derived from the federal Coastal Zone Management
Act of 1972 (Table 2.2-5). The first of these projects Inventoried
wetlands up to the 50-foot contour with the subsequent designation of
ecologically critical areas. The second effort principally dealt with
salt and brackish vegetative species mapping. Maps on a scale of
1:24,000 were produced for this study 1n 1976. The final two projects
concentrated on freshwater wetlands below the 10-foot contour. This
series of maps are at a scale of 1:24,000 using state-developed vegeta-
tion classification systems.
The U.S. Fish and Wildlife Service, as part of the National Wetlands
Inventory, has performed mapping in the two coastal counties (Figure
2.2-5). These maps were produced at a scale of 1:24,000.
In response to local and regional planning requirements, the USDA
Soil Conservation Service completed wetlands mapping 1n 1976 for the
Northeast Gulf Rivers Basin and the Alabama River Basin. This mapping
was prepared at a scale of 1:24,000 using USGS 7.5-m1nute topographic
maps as well as county photo Index maps (Alabama River Basin) and county
road maps when USGS maps were not available.
2-23
-------
IN PROGRESS
9 LARGE SCALE DRAFT OVERLAYS OR MAPS AVAILABLE
LARGE SCALE FINAL OVERLAYS OR MAPS AVAILABLE
• SMALL SCALE AND LARGE SCALE MAPS AVAILABLE
6 SMALL SCALE MAPS ONLY
Fiqure 2 2-4 Status of the National Wetlands Inventory in Florida.
Source: U.S. Fish and Wildlife Service. October 1983,
2-24
-------
TABLE 2.2-5
WETLAND INVENTORIES IN ALABAMA
Inventory coverage
Classification
Scale
Date Resolution
Agency
ro
ro
tn
Lower Mobile delta
(primarily freshwater
marshes)
Coastal wetlands up
to the 50' contour
(ecologically critical
areas)
Salt and brackish
habitats in Mobile and
Baldwin Counties up to
the inland/upland
boundary
Northeast Gulf Rivers
Basin
Alabama River Basin
All coastal wetlands in
Mobile and Baldwin
Counties below the 10'
contour, south of the
Hwy 90 causeway
Vegetational
(species)
Vegetational
(community)
Vegetational
(species)
Vegetational
(Martin et al.)
Vegetational
(Martin et al.)
Vegetational
(community)
1:24,000
1:62,500
1963
1975 1-3 acres
1:24,000 1976 1 acre
1:24,000 1976 20 acres
1:24,000 1976 20 acres
1:24,000 1981 1 acre
Ala. Dept. of Conservation
Pittman-Robinson Project
{F. X. Lueth)
Marine Environmental Science
Consortium
Dauphin Island Sea Lab
Marine Environmental Science
Consortium
Dauphin Island Sea Lab
USDA Soil Conservation
Service
USDA Soil Conservation
Service
Marine Environmental Science
Consortium
Dauphin Island Sea Lab
-------
TABLE 2.2-5
(continued)
WETLAND INVENTORIES IN ALABAMA
Inventory coverage
Classification
Scale
Date
Resolution
Agency
ro
i
ro
o>
Northeast Gulf Coast
Wetlands Mapping
(National Wetlands
Inventory)
All coastal wetlands
in Mobile and Baldwin
Counties below the 10'
contour, north of the
Hwy 90 causeway
Hydrology/Soils 1:24,000
Vegetation
(Cowardin et al.;
to the subclass and
water regime level)
Vegetational
(community)
1982
1 acre
1:24,000 1983 1 acre
U.S. Fish and Wildlife
Service
Marine Environmental Sciences
Consortium
Dauphin Island Sea Lab
-------
LEGEND
SEPTEMBER 1983
9 IN PROGRESS
» LARGE SCALE DRAFT OVERLAYS OR MAPS AVAILABLE
• LARGE SCALE FINAL OVERLAYS OR MAPS AVAILABLE
• SMALL SCALE AND LARGE SCALE MAPS AVAILABLE
© SMALL SCALE MAPS ONLY
Figure 2.2-5. Status of the National Wetlands Inventory in Alabama.
Source: U.S. Fish and Wildlife Service. October 1983.
2-27
-------
2.2.6 Mississippi
The Mississippi Bureau of Marine Resources produced coastal-wetlands
maps for Jackson, Harrison and Hancock Counties (Table 2.2-6). These
maps are at a scale of 1:24,000 and are intended for jurisdictlonal
applications for coastal wetlands protection. An inventory of estuarine
marshes in the Bay St. Louis, Biloxi and Pascagoula estuarine systems was
produced by the Gulf Coast Research Laboratory in 1973.
The U.S. Fish and Wildlife Service, as part of the National Wetland
Inventory, has performed mapping (Figure 2.2-6) in the three coastal
counties at a scale of 1:24,000.
2.3 SUMMARY
The U.S. Fish and Wildlife Service classification, developed for the
National Wetlands Inventory, is currently the most comprehensive wetland
classification system available. This system relies on vegetation,
hydrology and soil indicators for characterizing wetlands. It addresses
different user needs by providing different levels of detail, offers
regional consistency and recognizes significant ecological differences
among wetland types. The FWS classification 1s gradually being adopted
for use by most regulatory agencies.
Mapping efforts 1n the six Region IV coastal states were Inventoried.
Figures were used to depict the status of the FWS National Wetlands
Inventory as of October 1983.
2-28
-------
TABLE 2.2-6
WETLAND INVENTORIES IN MISSISSIPPI
Inventory coverage
Classification
Scale
Date
Resolution
Agency
Coastal Wetlands in
Jackson, Harrison and
Hancock Counties
no formal
classification
1:24,000
1973
1 acre
Miss. Marine Resources
Council (Bureau of Marine
Resources)
ro
10
Coastal Marshes
(St. Louis, Biloxi
and Pascagoula
estuarine systems)
Vegetatlonal
(Penfound &
Hathaway)
1:62,500 1973
Gulf Coast Research
Laboratory, Ocean Springs,
MS
Mississippi Coastal
Wetland Mapping
(National Wetlands
Inventory)
Hydrology/Soils 1:24,000
Vegetation
(Cowardin et a!.;
to the subclass and
water regime level)
1983
1 acre
U.S. F1sh and Wildlife
Service
-------
LEGEND
SEPTEMBER 1983
e IN PROGRESS
9 LARGE SCALE DRAFT OVERLAYS OR MAPS AVAILABLE
« LARGE SCALE FINAL OVERLAYS OR MAPS AVAILABLE
• SMALL SCALE AND LARGE SCALE MAPS AVAILABLE
6 SMALL SCALE MAPS ONLY
Figure 2.2-6.
Status of the National Wetlands Inventory in Mississippi-
Source: U.S. Fish and Wildlife Service. October 1983.
2-30
-------
2.4 LITERATURE CITED
Cowardin, L., V. Carter, F. Golet and E. LaRue. 1979. Classification of
wetlands and deepwater habitats of the United States. U.S. Fish &
Wildlife Service, Office of Biological Services, Washington, D.C.
#FWS/OBS-79/31. 103 pp.
EPA. 1983. Freshwater wetlands for wastewater management EIS. Phase 1
report. U.S. Environmental Protection Agency, Atlanta. EPA
904/9-83-107. 380 pp.
Martin, A.C., N. Hotchklss, F.M. Uhler and M.S. Bourn. 1953.
Classification of wetlands of the United States. U.S. Fish and
Wildlife Service, Washington, D.C. Special Scientific Report
Wildlife, No. 20:14 pp.
Penfound, W.T. and E.S. Hathaway. 1983. Plant communities in the marsh-
lands of southeastern Louisiana. Ecological Monographs 8: 1-56.
Shaw, S.P. and C.G. Fredine. 1956. Wetlands of the United States. U.S.
Fish and Wildlife Service, Washington, D.C. Circ. 39: 67 pp.
(cited in Cowardin et al., 1979).
2-31
-------
3.0 PROFILE OF EXISTING SALTWATER-WETLAND DISCHARGES
A survey was conducted to Identify and obtain
Information on existing saltwater-wetland
discharges. On-slte observations were made 1n
order to further understand the saltwater-wetland
systems and discharge methods In each state.
An Information survey program was Initiated to Identify and charac-
terize existing saltwater-wetland discharges In USEPA Region IV's six
coastal states. A 11st of possible wetland dischargers was obtained from
the appropriate state departments 1n North Carolina, South Carolina,
Georgia, Alabama and Mississippi. Florida reported no permitted
discharges Into saltwater wetlands. A survey form (Table 3.0-1) was then
sent to 154 designated dischargers. The Information obtained Includes
physical characteristics of the saltwater wetland, discharge frequency,
duration and amount, monitoring programs and any other special require-
ments. Phone contacts also were made In order to Identify possible
dischargers. The total number of saltwater wetland discharges surveyed
and the respondents are presented by state in Table 3.0-2.
Field trips to identified discharge sites also were conducted.
These on-site observations were made to further understand the saltwater-
wetland systems and discharge methods In each state. Sites In Alabama
and Mississippi were visited 1n August 1983; and North Carolina, South
Carolina and Georgia sites were visited 1n September 1983. Summaries of
these site visits and the results of the Inventory program conducted are
discussed by state in Sections 3.1 through 3.6.
3-1
-------
TABLE 3.0-1
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
SALTWATER WETLANDS FOR WASTEWATER MANAGEMENT EIS
WETLANDS DISCHARGE SURVEY
NAME OF DISCHARGER:
ADDRESS: ______
DATE:
DISCHARGE SOURCE:
(treatment plant, seafood processing, etc.)
Please describe the type of wetland you discharge to and wastewater
characteristics by answering the following questions.
1. Wetland Area Characteristics*
a. Size of wetland area, in acres
b. Area of land draining to wetland
area, in acres
c. Distance from wastewater discharge
to estuary or ocean/Gulf downstream
of wetland area, in feet
d. Vegetation (algae, weeds, grasses, etc.)
Approximate percentage
Type of wetland area covered
e. Soil (from county soil survey and other information)
Approximate percentage
Type of wetland area covered
*NOTE: If you discharge into a tidal river or creek, check here
and describe characteristics of the wetland closest to
your discharge. 3_2
-------
TABLE 3.0-1
(continued)
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
SALTWATER WETLANDS FOR WASTEWATER MANAGEMENT EIS
WETLANDS DISCHARGE SURVEY
2. Engineering Information
a. Total capacity of wastewater treatment
(gallons per day)
b. Wastewater treatment processes (specify capacity of each process
1n gallons per day)
1) Primary treatment
11) Secondary aeration and clarlfler(s) _____
111) Nutrient removal and other processes
1v) Storage ^^
Characteristics of wastewater entering wetland (yearly average)
1) Flow, 1n gallons per day
11) Biochemical oxygen demand, 1n mg/1
111) Suspended sol Ids, 1n mg/1
1v) Ammonia nitrogen, 1n mg/1
v) Chlorine residual, 1n mg/1
vi) Total nitrogen, 1n mg/1
v11) Nitrate & nitrite nitrogen, 1n mg/1
v111) Total phosphorus, In mg/1
1x) Ortho phosphorus, 1n mg/1
x) Other parameters (e.g. metals) _^^
d. Specify significant seasonal and/or more frequent variations 1n
wastewater characteristics:
e. Sludge treatment and disposal techniques:
f. Back-up method of wastewater disposal (1f any):
3-3
-------
TABLE 3.0-1
(continued)
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
SALTWATER WETLANDS FOR WASTEWATER MANAGEMENT EIS
WETLANDS DISCHARGE SURVEY
g. How long have you been discharging Into this water body?
What Is the frequency of discharge (dally, weekly, continuous,
etc.)?
h. List types of industry discharging to this treatment facility
(applies primarily to municipal discharges):
1) Type(s)
1i) Flow(s), in gallons per day
iii) Yearly average concentrations,
1f known, in milligrams per liter
- Metals
- Pesticides
- Other compounds (please specify)
1. Type of outfall for releasing wastewater to wetland area and
associated construction costs:
1) Channel
ii) Outfall pipe
111) Sprayers
1v) Other (specify type)
v) Year of Installation
3. Regulatory Requirements
a. Type and frequency of sampling
or 1n-stream monitoring
b. Special maintenance requirements
(if any)
c. Other special requirements due to
wetland discharge (1f any)
d. What 1s the water use classification of water body or wetland
receiving the discharge?
3-4
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TABLE 3.0-2
NUMBER OF SALTWATER-WETLAND DISCHARGES SURVEYED
BY STATE AND THE NUMBER OF RESPONDENTS
Survey Forms Number of
Number of Respondents
Discharging to
to Brackish Waters
State
North Carolina
South Carolina
Georgia
Florida3
A1 abama
Mississippi
Total
Distributed
60
29
34
0
12
19
154
Respondents (m
5
9
13
0
1
2
30
lostly Tidal Creeks)
2
8
7
0
0
2
19
^Florida officials indicated there were no saltwater wetland discharges,
therefore survey forms were not distributed.
3-5
-------
The difficulties in presenting a concise profile of saltwater
wetland discharges in USEPA Region IV involve wetland definition,
existence of discharges, and retrieval of information from individual
dischargers. Each state, as well as individual dischargers define a
saltwater wetland differently. Therefore, saltwater-wetland discharges
are not clearly identifiable. Individual states do not necessarily keep
records of permitted dischargers as distinctively saltwater or freshwater
wetland, or wetland/non-wetland users. Additional wetland dischargers
other than those named on lists provided by the states may be permitted
but are not readily identified as saltwater-wetland discharges.
The survey results show that there are no discharges directly onto
saltwater wetlands. The majority of respondents, however, identified
discharges into tidal creeks. The effects that these tidal creeks have
on an individual wetland are dependent on the physical, chemical and
biological components of that particular wetland. For example, due to
tidal fluctuation, not all tidal creeks inundate the surrounding wetland.
Because of the problem of wetland definition, respondents to the
questionnaire clearly had difficulty in describing the wetland into which
they discharge.
3.1 NORTH CAROLINA
The North Carolina Department of Natural Resources and Community
Development, Division of Environmental Management identified 60
discharges into waters classified as salt water within the coastal coun-
ties. Of the 60 discharges, three are from the Wilmington Region
3-6
-------
(southeast), and 57 are from the Washington Region (northeast). The
majority (39) of discharges in the Washington Region are seafood com-
panies (packing and/or processing plants), seven discharges are from
wastewater treatment plants and the remaining eight discharges are from
utilities, industry or unidentified. The three known discharges 1n
southeast North Carolina are municipal-wastewater treatment plants.
The total response rate of the 60 discharges surveyed was 8.3 per-
cent. Of the five responses, three Indicated non-saltwater wetland or
discontinued discharges. Since the majority of those surveyed did not
respond, the results are inconclusive. Specific information concerning
the discharge survey responses are included in Table 3.1-1.
Field trips were conducted in mid-September 1983 to two municipal-
waste treatment plants in coastal North Carolina. The findings of these
visits supplement the brief data received from the two other discharges.
Southport. North Carolina is served by the Southport Municipal
Wastewater Treatment facility which discharges Into Dosher Creek. This
small tidal creek is surrounded by Spartina and Juncus marsh. A stand of
cattails was near the discharge pipe, which was not clearly visible due
to vegetation cover.
Morehead City. North Carolina has been served by the Morehead
Municipal Wastewater Treatment facility since 1964, with a flow of
approximately 1 mgd. The biochemical oxygen demand and suspended sol Ids
limitations are 30 mg/1. The facility discharges Into Calico Creek, a
3-7
-------
TABLE 3.1-1
PROFILE OF SALTWATER WETLAND DISCHARGES IN USEPA REGION IV BASED ON SURVEY RESPONSES
Distance (ft) Tine Total Waste-
from discharge to Discharge since capacity water treat- Yearly
Wetland estuary/ ocean/Gulf to tidal discharge of waste- ment processes, average
.State/ size downstream of creek or began Discharge water treat- capacity of each flow BODc
Discharge (acres) wetland Vegetation river (>TS) frequency ment(MGD) process (MGD) (MGD) (mg/1)
North Carolina
Municipal Wastewater NA NA NA Yes
Treatment Plant
Seafood Processing NA NA - Yes
Plant
South Carol ina
Subdivision - ves
Treatment Plant
CO
oc
Public Wastewater 46 Approximately Weeds, grass, Yes
Treatment Plant 2500 to 3000 80% tupelo,
red maple,
etc.
Public School - Approximately Spartina Yes
Treatment Plant 200 from
high water mark
of tidal creek
Municipal Hastewater - Approximately Marshgrass Yes
Treatment Plant 3000
Municipal Wastewater - - . yes
Treatment Plant
Apartment Complex - - Marshgrass Yes
Treatment Plant
19 Continuous 4.0 Primary-4.0 2.9 28
Secondary-*. 0
25.5 6 da/week 0.000008 Primary
8 mo/yr (chlorine)
Continuous 0.035 Secondary aeration* 0.18 17
clalrifer 20,115 to
gpd 0.025
Storage 7,875 gpd
1 mo. Daily 5.0 Primary 2.5 0.3 10
Secondary 2.5
Polishing pond
Storage 5.0
11 5 da week 0.04 Secondary 0.06 0.0074 5
9 mo/yr Storage 0.002
15 Continuous 1.5 Primary 1.5 1.0 10
Secondary 1.5
Began - 2.0 Primary 2.0 2.0 30
10/1/83 Secondary 2.0
8 - 0.035 Primary 0.035 0.019 15
Secondary 0.035
Nutrient removal
storage 0.035
Sus-
pended Type
solids of
(mg/1) outfall
14 Drainage
ditch
-
20 Pipe
15 Pipe
with
diffuser
header
7 Pipe
10 Pipe
30 Pipe
15 Pipe
Treatment Facility
Approximately
3.5 miles to
Atlantic Ocean
Marshgrass Yes
15
Continuous 0.0075
15
15
-------
TABLE 3.1-1
(continued)
PROFILE OF SALTWATER WETLAND DISCHARGES IN USEPA REGION IV BASED ON SURVEY RESPONSES
Distance (ft) Time Total Waste-
from discharge to Discharge since capacity water treat- Yearly
Wetland estuary/ocean/Gul f to tidal discharge of waste- raent processes, average
State/ size downstream of creek or began Discharge water treat- capacity of each flow 6005
Discharge (acres) wetland Vegetation river (yrs) frequency ment(MGD) process (MGO) (MGD) (mg/1)
Georgia
Paper Company 1,120 0 75-80% Yes 42 Continuous 44
Industrial Treatment Grasses (31 yrs
Facility untreated;
11 yrs
treated
Pulp and Paper Mill Discharge 90%
is to 100,000 to Spartina Yes 50+ Continuous 33
estuary ocean
Municipal Treatment - - - Yes 8 Daily 0.550
Plant
Municipal Treatment - - Weeds, grass Yes 10 Daily 1.0
Plant etc.
Municipal Treatment - - Yes 22 Continuous 0.85
Plant
Municipal Treatment Not Not
Plant measured measured Unknown - 40+ - 2.25
Municipal Treatment - - Yes - Daily 0.368
Plant
Mississippi
Treatment Plant 20 1000 to estuary 805 Yes 23 Daily 0.27
Marshgrass
Treatment Plant 10 2000 95, Grass/ 11 Continuous 0.008
to weeds
500
Primary 44 36.994 21
Secondary 44
Primary 33 30 50
Secondary 33
Secondary 0.500 10
Primary 0.85 NA NA
Secondary 0.85
Secondary 0.3
Storage (15.1 0.3
acre-pond)
acre-pond)
Primary 2.50 1.3 < 10
Secondary 2.25 to
Storage/ 2.25 1.6
Nutrient Removal
Primary 0.368 0.255 2.7
Secondary 0.368
Primary 0.27 0.22 20
Secondary 0.27
Primary 0.008
Secondary 0.008
Nutrient Removal
0.008
Sus-
pended Type
sol ids of
(mg/1) outfall
39 Pipe
75
10 Pipe
NA Pipe
Pipe
<10 Pipe
3.2 Pipe
5 Pipe
Roadside
ditch
NA indicates the respondent did not have the information available.
- indicates the respondent did not answer.
Flout ire presented in mgd, million gallons per day, unless otherwise noted.
-------
tidal creek surrounded by marsh. High water levels prevented access to
the immediate point of discharge. Downstream from the discharge point,
active shrimp harvesting was occurring in waters that were posted.
3.2 SOUTH CAROLINA
A list of 29 individual municipal and industrial discharges to salt-
waters was provided by the South Carolina Department of Health and
Environmental Control, Bureau of Water Pollution Control. The profile
described is based on eight responses; one questionnaire response indi-
cated that the treatment facility was still in the planning stage and had
not been constructed.
The wastewater treatment plants responding to the questionnaire in
South Carolina all discharge to tidal creeks. These discharges do not go
directly to saltwater marsh areas, however, some marsh areas may be inun-
dated during high tide.
Typical vegetation in South Carolina saltwater wetlands is comprised
of marsh grasses such as Spartina or Juncus. One respondent specifically
reported 80 percent coverage by swamp tupelo, red maple, black willow,
tallow tree, sweet gum and water elm (indicative of freshwater wetlands)
along with weeds, grasses and shrubs. The individual sizes of the
wetlands are generally unknown. The frequency of discharge ranges from
daily to continuous, and the period of discharge ranges from one month to
15 years. The typical effluent discharged into saltwater wetlands is
secondary-treated domestic sewage. This treatment process involves a
3-10
-------
minimum of secondary aeration and clarification. The yearly average flow
ranges from 0.007 mgd to 2.0 mgd from discharge pipes. Table 3.1-1 pre-
sents individual responses to the survey.
Field visits conducted in September supplement the survey data and
allow first-hand knowledge to be gained concerning the wetland systems
and the different types of discharges in South Carolina. The two munici-
pal wastewater treatment plant discharge sites visited are discussed
below.
Mt. Pleasant. South Carolina is serviced by three facilities - the
Sneefarm Subdivision, the Main Plant and the Parish Place Plant. The
three are reportedly going to be combined Into one facility in the near
future. A site visit was made to the Main Plant in Mt. Pleasant, a 1.5
mgd facility serving Mt. Pleasant since 1968. The plant will be upgraded
to approximately 3 mgd. Ultraviolet disinfection technology will be used
when the upgrading is completed. The facility discharges into a tidal
creek that flows through a saltwater marsh leading to the Intracoastal
Waterway. At high tide the tidal creek is noted to be rich with mullet.
St. Andrews, South Carolina public service district is served by a
standard secondary-treatment plant using aeration and clarifiers. Drying
beds are used for sludge treatment, after which the material Is disposed
of in an approved landfill. The Pierpont Plant discharges 1.5 mgd Into
nearby Church Creek and has been operating continuously for 15 years.
Depending on tidal fluctuations, two other small creeks may also be inun-
dated. The tidal area is surrounded by Spartina and Juncus marsh.
3-11
-------
3.3 GEORGIA
The state of Georgia provided the highest percentage of returned
Information forms. The Georgia Environmental Protection Division, Water
Protection Branch provided a list of 34 known Industrial and municipal
saltwater-wetland discharges of which 13 responded to the questionnaire.
These 13 Included five industrial discharges, seven municipal discharges
and one utility. Information provided by the 13 dischargers Indicated
that only seven actually discharged effluent to a saltwater area. One
Industrial respondent reported they discharged directly Into an estuary,
however, they did not consider this a wetland and did not complete the
questionnaire.
Information reported by the seven dischargers to saltwater areas
generally indicated discharges to tidal creeks. The size of each par-
ticular wetland is not reported except for one case 1n which the wetland
is 1,120 acres. The type of vegetative cover Is either unknown or
described as weeds or marsh grasses. Respondents indicate that they have
been discharging secondary-treated wastewater on a daily or continuous
basis for an overall average of 30 years. The yearly-average flow
discharged ranges from approximately 0.3 mgd of domestic wastewater to 37
mgd of industrial wastewater. Table 3.1-1 profiles existing saltwater-
wetland discharges 1n Georgia.
The discharges of three different facilities were observed during
site visits conducted in mid-September 1983. The following narratives
discuss the site visits.
3-12
-------
St. Simons Island. Georgia 1s served by a 1.3 mgd wastewate/ treat-
ment facility that has operated since 1945. Characteristics of the
effluent Include a BOD limitation of 20 mg/1 and a suspended solids limi-
tation of 30 mg/1. The discharge flows Into Dunbar Creek which Is
tidally Influenced. The creek Is within a Spartlna/Juncus saltwater
marsh and contains many tarpon and mullet 1n the vicinity of the
discharge. Spartina near the point of discharge appeared taller and
denser than that not proximal to the discharge.
Wilmington Island. Georgia 1s served by the Wilmington Park Sewage
Treatment Plant. This 200,000 gpd to 300,000 gpd treatment facility
discharges to a tidal creek narrowly bordered by Sa11corn1a and Spartina.
This tidal creek eventually flows Into the Wilmington River. Spartina at
the mouth of the creek was not noticeably different from that farther
along the river's shore.
Skidaway Island. Georgia 1s the location of Skldaway Island
Utilities which operates a spray-Irrigation system. The total capacity
of wastewater treatment 1s 750,000 gpd. Sprayers have been used dally
for the last nine years. The area sprayed 1s woodland and most
wastewater percolates Into the ground. Overflow washes Into a canal
which, in turn, drains Into a marsh.
3-13
-------
3.4 FLORIDA
The Florida Department of Natural Resources, Division of Marine
Resources reported that the state of Florida has not permitted any
saltwater-wetland dischargers. A 201 Study is being prepared that is
investigating the feasibility of using a saltwater wetland for wastewater
discharge in Jacksonville Beach, Florida, yet there are no existing
applications of wastewater onto saltwater marshes. Questionnaires there-
fore were not distributed in the state. A variety of other wetland eco-
systems exist in Florida that are used as discharge sites for treated
wastewater and they are detailed 1n this document's companion report for
the Freshwater Wetlands EIS.
3.5 ALABAMA
The state of Alabama had the lowest percentage response to the
wetland-discharge questionnaire mailed. One negative response was
received from a list of 12 potential saltwater-wetland discharges pro-
vided by the Water Division of the Alabama Department of Environmental
Management. The respondent reported that they did not fit any of the
categories mentioned in the survey.
Four municipal and two seafood-processing discharges were visited in
coastal Alabama to examine the wetland systems. Three of the municipals
were non-saltwater wetland discharges. The saltwater areas are discussed
in the narratives that follow.
3-14
-------
Bon Secour, Alabama was the site of one seafood processor visit.
Although the rate of discharge could not be determined, the small size of
the operation suggested that the rate of discharge would be low.
Discharge was directly into a large bayou. There was a Spartina fringe
along the bayou at this site, but the banks were fairly elevated and not
considered wetland marsh.
Bayou La Batre, Alabama is serviced by a sewage-treatment plant
that discharges directly into Portersville Bay through a discharge pipe
that crosses a saltwater wetland. This plant was designed to handle 1
mgd but, because of the number of seafood processors in Bayou La Batre
(one of which was visited), the ability of this plant to adequately pro-
cess the large volume of wastes is severely limited, particularly during
the summer months when processing activity is at a peak.
Pt. Aux Pins, Alabama is a predominantly Juncus saltwater wetland
near Bayou La Batre. This marsh was visited because it is the site for a
proposed demonstration project to assess the feasibility and effects of
applying wastewater discharge onto a saltwater marsh. The proposed study
would use wastewater from a seafood-processing plant at Bayou La Batre
and spray irrigate wastewater on various marsh plots.
3.6 MISSISSIPPI
The Mississippi Department of Natural Resources, Bureau of Pollution
Control provided a list of 19 private and industrial discharges from
three Mississippi Gulf counties. The profile 1s based on a 10 percent
response rate.
3-15
-------
The two responses were not clearly Identified as saltwater wetland
discharges. One treatment plant serves a utility and discharges to a
bayou. This plant has operated for 23 years, discharging approximately
270,000 gpd of secondary treated wastewater. Sludge is disposed of at an
approved sanitary landfill. The wetland is approximately 20 acres, and
80 percent of the acreage 1s marsh grass. The second respondent reported
discharge to a roadside ditch. The wetland vegetation is 95 percent
grass and weeds over an area that measures from 10 to 500 acres. The
yearly average flow for this treatment plant is 8,000 gpd for the past 11
years. The respondent Indicated that the ditch is solely for industrial
use. Table 3.1-1 specifies the details of the two questionnaire respon-
ses for Mississippi.
It is difficult to assess saltwater wetland discharges in
Mississippi as well as in the other states because of the lack of clearly
defined wetlands. Field visits were conducted in August 1983 to examine
saltwater-wetland systems and discharges 1n Mississippi and are discussed
below.
Pass Christian. Mississippi municipal treatment plant 1s designed to
discharge 700,000 gpd. Discharge is into a small ditch which eventually
enters a Juncus marsh adjacent to Portage Bayou. There was no means of
access to the area where the ditch entered the marsh.
3-16
-------
Discovery Bay, Mississippi Is a housing and marina development on
Portage Bayou at Pass Christian. At present, only the marina and a few
townhouses have been constructed. Sewage 1s treated by a package plant
that discharges less than 1,000 gpd through a pipe at the edge of the
bayou. Juncus was the predominant vegetation at the point of discharge.
No difference was observed between vegetation at the point of discharge
and that farther along the shore away from the discharge point.
Diamondhead. Mississippi Is a large residential development that
includes a golf course, tennis courts and a marina. Sited on the north
shore of St. Louis Bay, this development had one package plant that
discharged into salt water. At the time of our visit, only a few homes
were serviced by this unit and discharge was less than 1,000 gpd. This
discharge entered a ditch which flowed Into a large tidally - Influenced
channel bordered by marsh on the far side of the discharge ditch.
3.7 SUMMARY
The response (19.5 percent) to the survey questionnaires was con-
sidered low. Of the 30 responses obtained, the majority (19) indicated
that they discharged into brackish waters, mostly into tidal creeks.
None stated that they discharged directly onto saltwater wetlands.
During the site visits, wastewater discharges into tidal creeks were
observed on several occasions. Marsh vegetation at the mouth of or bor-
dering these creeks appeared taller and denser at one site but, for the
most part, did not appear to differ from adjacent areas less likely to be
Influenced by the discharge.
3-17
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4.0 INSTITUTIONAL CONSIDERATIONS
The objective of this section 1s to present and
discuss federal Institutional requirements which
govern the use of saltwater wetlands as a receiving
body for wastewater discharges and to describe the
Region IV regulatory programs administered by the
Individual states. Unresolved Institutional Issues
are also addressed.
A large part of federal institutional involvement pertaining to
wastewater discharges in saltwater wetlands stems from the Clean Water
Act. Programs established through the Act and discussed here are the
Water Quality Standards Program as administered by U.S. Environmental
Protection Agency (EPA); the National Pollutant Discharge Elimination
System Permit Program also administered by the U.S. EPA; the 201
Construction Grants Program, also under U.S. EPA administration; and the
Dredge and Fill Permit Program administered by the U.S. Army Corps of
Engineers. Two other federal programs, Fish and Wildlife Coordination
(which involves the U.S. F1sh and Wildlife Service and National Marine
Fisheries Service responsibilities) and the National Shellfish Sanitation
Program administered by the Public Health Service, both involve advisory
duties when a proposed water resource development activity could adver-
sely impact fish, wildlife or shellfish of a given water body.
State programs or procedures which Impact the feasibility of
discharging wastewater to saltwater wetlands are presented in this
chapter. These programs and procedures include water quality standards,
discharge permits and methodology for determining wasteload allocations
for wetlands, the process for prioritizing projects for 201 Construction
4-1
-------
Grant Program funding, and various state coastal area management and pro-
tection plans.
The most significant issue which is addressed in this chapter 1s the
procedural and regulatory variation among the various programs which deal
with saltwater wetlands. These differences Include:
lack of consistency 1n defining a saltwater wetland, Including
Its landward and seaward boundaries;
variation in the number of water use classifications and stan-
dards which may apply to saltwater bodies;
differences 1n assigning water quality standards to similar use
classifications, e.g., shellfish harvesting waters;
variation in evaluating the effects of proposed discharges on
wetlands.
All of these differences -are In themselves Issues that will be
significant in permitting activities within saltwater wetlands in the
states and also along state boundaries or Interstate waters.
4.1. FEDERAL PROGRAMS
4.1.1 Water Quality Standards Program
The Water Quality Standards Program (40 CFR 131.2) 1s the foundation
of the nationwide strategy for water quality management. Section 303 of
the Clean Water Act authorizes establishment of water quality standards
to protect public health, public welfare and water quality. Each state
has the responsibility of developing water quality standards, while the
U.S. EPA has review and approval authority. Permits for any construction
activities and discharges are Issued or denied based primarily on
adherence to water quality standards.
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Stream segments are delineated, and associated use classifications
are established as part of a state's Water Quality Management Plan.
Water quality criteria are then established to assure that designated
uses will be maintained and protected. Effluent limitations for each
wastewater management facility that discharges to waters of the U.S. are
determined to meet established water quality criteria. For an effluent-
limited segment, secondary treatment Is required of publicly-owned treat-
ment works (POTWs). For a water quality-limited segment, additional
treatment may be required, dependent on the number and type of pollutant
sources within and upstream from the segment. An effluent-limited
segment 1s one where water quality standards will be met If POTWs provide
secondary treatment of effluent. A water quality-limited segment 1s one
where standards will not be met by POTWs providing secondary treatment
alone, and this failure necessitates Implementation of more advanced
treatment controls or strategies.
Current regulations associated with water quality standards do not
Include rigid technical procedures for states to utilize 1n revising
water quality standards. However, federal regulations for water quality
standards revised 1n November 1983 now offer Increased guidance for
determining use attainability, utilizing site-specific criteria, applying
anti-degradation policy, varying (upgrading or downgrading) levels of
aquatic protection and applying general policies on mixing zones and
variances.
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Key considerations are: assessing the attainability of the
designated water use, defining natural background conditions, whether to
develop general or site-specific standards, and protection of downstream
water uses.
Regarding uses of wetlands as waters of the United States, most
wetlands in Region IV are designated for the same usage as the adjacent
water body, generally fish and wildlife use. Water quality standards are
numerically established at minimum levels for attaining the designated
use. Discharges of wastewater can not be allowed to reduce water quality
below the level needed to maintain the designated water use. At the same
time, the designated water use cannot Imply that degradation of existing
water quality is warranted. Natural background conditions need to be
defined in order to determine the water use that Is attainable. Clearly,
dischargers should only be required to maintain water quality require-
ments that correspond to water uses attainable without the discharge.
Dissolved oxygen and pH in wetland waters are quality constituents that
are typically lower than standard limits due solely to natural con-
ditions.
Site-specific water quality standards can be established by states.
Compared to more general all-Inclusive standards, site-specific standards
are more likely to achieve the designated water use without being more
stringent than necessary. On the other hand, field procedures on which
to base site-specific standards can be time-consuming and expensive.
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Finally, water quality standards for a wetland may need to be
established so that the water quality use classification of a downstream
estuary or coastal bay can be attained. Effects of downstream water uses
may be less noticeable for saltwater wetlands than they are for fresh-
water wetlands that may, for example, be located upstream of a water
supply Intake. Designated water uses for an estuary or coastal bay that
may be more stringent than wetland water uses Include swimming or
shellf1sh1ng. Because waters can move from a downstream estuary or
coastal bay upstream to a wetland, downstream water use designations also
can affect a saltwater wetland in a direct manner.
Each of the Region IV coastal states maintains different water use
classifications as shown in Table 4.1-1. No standards have been deve-
loped based on environmental characteristics of the various wetland
types. North Carolina and South Carolina do designate that wetland
waters can have dissolved oxygen concentrations and pH levels which, due
to natural conditions, fall below normal standards for non-wetland
waters.
Florida and Georgia have specially designated certain waters as
"outstanding" state waters. Wetlands within or upstream of "outstanding"
state waters may be subject to more strict discharge limitations than if
the "outstanding" state waters designation 1s not 1n effect.
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TABLE 4.1-1
AGENCIES AND WATER USE CLASSIFICATIONS FOR EPA REGION IV COASTAL STATES
State
Al abama
Florida2
Agency
Department of Environmental Management,
Water Division
Department of Environmental Regulation,
Division of Environmental Programs
Water use classifications which can apply to Coastal
Class B - Swimming and other whole body water contact
Class C - Shellfish harvesting
Class D - Fish and wildlife
Class E - Agriculture and industrial water supply
Class F - Industrial Operations
Class G - Navigation
Class II: Shellfish propagation or harvesting
Class III: Recreation, propagation and management of
Waters
sports
Georgia
4
Mississippi
North Carolina
South Carolina
Department of Natural Resources,
Environmental Protection Division,
Water Protection Branch
Department of Natural Resources,
Bureau of Pollution Control,
Water Division
Department of Natural Resources and
Community Development, Division of
Environmental Management
Department of Health and Environmental
Control, Bureau of Water Pollution
Control
fish and wildlife
Class IV: Agricultural and industrial water supply
Class V: Navigation, utility and industrial use
Outstanding Florida waters
Class B: Recreation
Class C: Fishing, propagation of fish, shellfish,
game and other aquatic life
Class D: Agricultural
Class E: Industrial
Class F: Navigation
Class G: Wild river
Class H: Scenic river
Class I: Urban stream
Class B - Shellfish harvesting areas
Class C - Recreation
Class D - Fish and wildlife
SA - Shellfish waters
SB - Primary Recreation
SC - Fishing and secondary recreation
SAA - Outstanding resource waters
SA - Shell fishing waters
SB - Primary recreation waters
SC - Secondary recreation and fishing waters
NOTES: The state of Alabama has not developed a specific saltwater use classification system. Of these water use
classifications, several can be applied to saltwater use, including: 'B1, 'C1. 'D', and "G1.
2
The state of Florida has not developed a specific saltwater use classification system. Of these water
use classifications, several can be applied to saltwater use, including: Class II, Class III, Class V
and Outstanding Florida Waters.
The state of Georgia has not developed a specific saltwater use classification system. Of these water
use classifications, several can be applied to saltwater use, Including: Class B. Class C and Class F.
4
The state of Mississippi has not developed a specific saltwater use of classification system. Of these
water use classifications, several can be applied to saltwater use, including: 'B1, 'C' and '0*.
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4.1.2 National Pollutant Discharge Elimination System (NPDES) Permit
Program
4.1.2.1 Regulatory Background/Overview
Section 402 of the Federal Water Pollution Control Act (PL 92-500,
as amended) established the National Pollutant Discharge Elimination
System process for permitting all point source pollutant discharges Into
the waters of the United States. This permit process 1s applicable to
all potential dischargers to saltwater wetlands. Additionally, in accor-
dance with this Act, all municipal dischargers were to achieve secondary
treatment by 1 July 1977, unless stricter controls were needed to meet
water quality standards. Pursuant to Section 402, the Environmental
Protection Agency (EPA) or an EPA-approved state agency must issue an
NPDES permit prior to the discharge of wastewater Into U.S. waters. An
NPDES permit, when Issued, should Include (at a minimum):
. effluent limits,
. schedule for complying with effluent limits,
. monitoring and reporting requirements, and
. sludge disposal reguirements.
Depending upon the nature of the receiving waters and/or the
surrounding environment, special protection procedures may be required as
part of the permit. This may be true for wetland areas that are con-
sidered to be valuable and sensitive ecosystems. Special requirements
are discussed in Section 4.1.2.2.
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Section 318 of the Act approves and permits aquaculture systems
under the NPDES program. An "aquaculture project" 1s a "managed water
area which uses discharges of pollutants Into that designated area for
the maintenance or production of harvestable freshwater, estuarlne, or
marine plants or animals" (40 CFR 122.56). The EPA Administrator is
authorized to promulgate regulations establishing procedures and guide-
lines appropriate to the "discharge of a specific pollutant or pollutants
under controlled conditions associated with an approved aquaculture
project" Section 318(a), CWA . In addition, following EPA approval,
each state is authorized to administer its own aquaculture permit
program.
4.1.2.2 NPDES Permitting Process and Us Relationship to Wastewater
Management Saltwater Wetlands
NPDES permit Issuance is typically based on compliance with
established water quality standards and waste load allocations for a par-
ticular receiving water body. Wetland discharges are required to be per-
mited under NPDES regulations.
General permits may be written to cover a category of discharge
types within a particular geographic or political area. These permits
are usually written for similar types of discharge sources, and carry
requirements specific to that discharge type. Currently, this measure 1s
interpreted as permitting only groups having similar discharge sources.
Groups with similar discharge sites, such as wetlands, are not Included
under this regulation even though some groups of wetland discharges could
meet the regulatory requirements. It 1s possible, however, that there
are discharges to wetlands currently permitted under this mechanism.
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Prior to discharging to a U.S. water body, an NPDES permit applica-
tion must be submitted to EPA or to an EPA-approved state environmental
agency. The following items must be included on the NPDES permit
application:
. list of all pollutants which may be apparent within wastewater
and which must comply with water quality requirements,
. average and maximum quantities of wastewater to be discharged,
. frequency and volume of discharge, and
. name/type of receiving water.
The amount of detail to be provided on an application varies
according to the size of the discharge. Small domestic discharges are
required to provide the least level of detail on the permit. For
instance, Federal Short Form A for municipalities and Short Form D for
commercial establishments ask applicants for the name of the receiving
water, not the type (such as wetlands). Characteristically, wetland
discharges in EPA Region IV tend to be small and many are commercial
establishments (I.e. seafood processing plants). Therefore, the Short
Form would be applicable. Larger discharges (>5 MGD) generally use Form
2C which requires more detailed Information on receiving waters.
Another consideration In the NPDES permitting process 1s the
establishment of a wasteload allocation, or the maximum dally wasteload
allowable. Wasteload allocations are established for all state surface
waters so that water quality standards can be met and designated uses
protected through consideration of background conditions and pollution
sources along a designated water body segment. Effluent limits are then
assigned to the Individual dischargers Into that water body segment.
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An area of discharge 1s determined to be either effluent-limited or
water quality limited before wasteload allocations are set. If it 1s
effluent-limited, then technology-based treatment requirements are made a
part of the permit requirements and represent a minimum level of treat-
ment required. For publicly owned treatment works discharging to
wetlands, this would probably represent at least secondary treatment
prior to discharge. If, however, water quality standards can not be met
with secondary treatment, then 1t 1s considered a water quality-limited
segment and thus more stringent effluent limits must be established to
maintain 1n-stream water quality standards.
Pursuant to federal requirements of the NPDES program, the
discharger, following application approval, 1s responsible for giving the
following information to the regulatory agency:
. schedule for commencing discharge,
. design plans for location and type of outfall,
. construction procedures, and
. start-up and monitoring procedures.
In addition, the permitting agency can periodically inspect discharge
facilities to determine whether Implementation procedures are being con-
ducted properly. Such authority applies for both municipal and seafood
processing discharges.
The NPDES permit can Include special requirements that a discharger
must meet. These requirements might be necessary, for Instance, when the
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receiving water body is a wetland and special measures are needed to pro-
tect established uses or attain applicable water quality standards or
effluent limits. Special requirements can include {but are not limited
to):
. seasonal or more frequent variations in discharge or monitoring
requirements,
. outfall design to enhance wastewater distribution and assimila-
tion,
. special treatment operation or maintenance,
. wastewater disinfection requirements,
. requirements conditional on future events,
. sludge management requirements, and
. special operator training.
4.1.3 201 Construction Grants Program
4.1.3.1 Regulatory Background
The 201 Construction Grants Program was authorized by Section 201 of
the Clean Water Act. The program constitutes the procedures required to
obtain Federal funding for the planning, design and construction of muni-
cipal wastewater treatment systems. Fundable systems include those for
collection, treatment and disposal of wastewater. Amendments were made
in 1982 to the 201 Program affecting the scope and funding percentages of
wastewater facilities projects (Section 4.1.3.2). The 201 Program is
applicable to saltwater wetlands only when a municipality wishes to
receive a construction grant for a treatment facility which will
discharge to a saltwater wetland. The availability of construction grant
funding for wetland alternatives is based on the process by which the
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applicable state prioritizes 201 projects and the degree to which the
control or access of wetlands are required and eligible.
4.1.3.2 Construction Grants Process
This section discusses the three steps to the construction grants
program and recent changes, with emphasis on applicability to saltwater
wetlands disposal.
. Step 1 - facilities planning,
. Step 2 - facilities design, and
. Step 3 - facilities construction.
Generally, these three steps take place in consecutive order except 1n
cases where Steps 2 and 3 are blended together.
Some portions of the construction grants process have been revised
since 1981:
. Grants for Steps 1 and 2 are no longer given separately; Instead,
allowances are included in Step 3 grants for facilities planning
and design activities.
. Step 3 grant advances are possible for small communities from the
state environmental agency.
. Construction grants are now available only for secondary or more
stringent treatment, new interceptors and connecting sewers and
infiltration/Inflow corrections.
. After October 1, 1984, grants will be made to handle current
needs, not to exceed year 1990 needs.
. Engineering services are required and fundable for one year after
construction completion.
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. Secondary treatment definition has been expanded to Include
oxidation ponds, lagoons, ditches and trickling filters.
The fundability potential of a discharge system to wetlands as a means of
wastewater management and the applicability of EPA's Innovative/
alternative technology program are not defined.
Step 1 of the construction grant process (Facilities Plan) must pre-
sent all possible wastewater management alternatives, evaluate feasible
alternatives and select a preferred alternative. This preferred alter-
native must meet the following conditions:
. must be needed to Improve existing conditions and/or conditions
20 years Into the future,
. be cost effective when considering costs, environmental Impacts,
financial considerations, reliability, energy use, Implemen-
tablHty and recreation,
. Involve the public, and
. conform to an approved water quality management plan and waste-
load allocations.
As part of the evaluation of alternatives, environmental Impacts
must be considered Including possible permits which may be required based
on activities and potential Impact. For Instance, 1f dredging and
filling of a wetland 1s part of an alternative being evaluated, the Corps
of Engineers must be consulted. If a dredge and fill permit would be
required, the Corps will Identify alternative locations and other
environmental considerations.
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Mitlgattve measures must be Introduced 1f 1t 1s determined that
sensitive environmental areas (Including wetlands) will be Impacted by
the preferred alternative. Environmental Impacts which may be considered
with a potential discharge to saltwater wetlands Include:
. Impacts on listed endangered or threatened species,
. Impact on water quality for designated uses, e.g., recreation.
shellfish harvesting,
. visible changes, I.e., Increase or decrease or change 1n vege-
tation type or turbidity which may negatively Impact fish and
wildlife habitat,
. Impacts during construction, and
. public health.
Present regulations require the preparation of an EIS If there Is
potential for significant adverse Impacts on wetlands, or 1f any major
portion of the treatment works 1s located within a wetland area. Other
conditions may also necessitate preparation of an EIS.
Following completion of a draft facilities plan, an opportunity for
review 1s provided by federal, state and local agencies. The federal
role 1n this process varies from state to state, contingent upon whether
a state has been delegated facilities plan review and approval authority.
Many problems can occur to hamper facilities planning efforts, par-
ticularly 1f efforts required of other agencies are not completed. For
Instance, 1f the Involved state(s) has not developed a wasteload alloca-
tion for the water body proposed to receive treated wastewater, planning
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efforts may be delayed. Another fairly recent stipulation to the 201
process is the result of 1981 Amendments to the Clean Water Act. These
amendments specify that each state review and, if necessary, revise its
water quality standards by December 29, 1984 or the issuance of construc-
tion grant funds would be stopped.
Design (Step 2) and construction (Step 3) procedures do not vary
greatly from project to project. Once a project is high enough on the
state priority list certain procedures need to be followed in order to
assure construction grant funding eligibility. Considerations associated
with a project which includes a wetland discharge are:
. possible need for a dredge or fill permit under Section 404 of
the Clean Water Act,
. field testing of innovative/alternative technologies,
. specification during design phase of construction and operation-
maintenance methods associated with chlorine/other disinfectant,
since worker safety and chlorlne-wastewater by-products on
wetlands are of primary concern,
. construction specifications as output from design phase can
include methods to minimize wetland disturbance, maximize wetland
and assimilative capacities and other mitigative and/or enhance-
ment measures,
. plan of operation must include any unique staff needs and timing
considerations for construction, start-up and operation,
. an operation and maintenance manual to include start-up and
operation procedures associated with wetlands use,
. construction activities monitoring must also be provided, and
. after construction starts, one year of engineering services is
needed to supervise and train operator/troubleshoot serious
problems.
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4.1.4 Corps of Engineers Permit Program
Thfc Dredge and Fill Permit Program 1s administered by the Corps of
Engineers (COE) as promulgated by Section 404 of the Federal Water Pollu-
tion Control Act Amendments of 1972 (PL 92-500). Section 404 authorizes
the Secretary of the Army, through the Chief of Engineers, to issue or
deny permits for disposal of dredged or fill material in the waters of
the United States.
A Section 404 Dredge and Fill Permit may be required 1f the
discharge of dredge or fill materials 1n waters of the United States will
occur as a result of construction of wastewater facilities 1n wetland
areas. Dredging 1n saltwater wetlands can take place for a number of
reasons related to wastewater discharges, Including:
. pipeline construction,
. channels, aerators, weirs, levees and storage ponds for
controlling the flow and distribution pattern of wastewater, and
. other alterations for improving system efficiency.
The Corps' responsibilities 1n terms of the use of wetlands for waste-
water discharges are limited to 404 permit review and issuance. As such,
they are not directly Involved in the permitting of wetlands for
wastewater discharge.
The Corps' dredge and fill permitting process begins with a prelimi-
nary assessment and application submlttal to determine the extent of
environmental reviews required, ranging from a categorical exclusion to a
full EIS procedure. In the case of categorical exclusion, no application
1s required.
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Public notice* including the findings of the preliminary assessment,
is then given to all interested parties and to agencies with a required
role in the process. This step in the Corps' review process is espe-
cially significant since it gives public agencies at all government
levels, private groups and individuals the opportunity to voice comments
on all the effects of project construction and operation (including
social, economic and environmental factors affecting wastewater manage-
ment in saltwater wetlands).
If necessary, a public hearing is held, the consents are evaluated
and any environmental reviews necessitated in the preliminary assessment
are conducted. Following completion of the environmental review, the
permit decision 1s made and the application is either issued or denied.
Table 4.1-2 presents a summary of the criteria the Corps considers in
their permit decision-making process.
In addition to the Corps review of dredge and fill permit applica-
tions, the EPA also shares certain responsibilities. Input to the permit
review process is also provided by the Department of Interior, F1sh and
Wildlife Service (FWS), and the Department of Commerce, National Marine
Fisheries Service (NMFS). The F1sh and Wildlife Coordination Act and the
National Shellfish Sanitation Program and their relationship to
wastewater disposal in saltwater wetlands 1s discussed in Sections 4.1.5
and 4.1.6, respectively.
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TABLE 4.1-2
CORPS OF ENGINEERS PERMIT EVALUATION CRITERIA
. Evaluation of economic, social and environmental costs versus bene-
fits
. Extent of public and private need
. Desirability of alternative locations
. Cumulative Impacts
. Effects on wetlands
. Conservation of wildlife and prevention of direct and Indirect losses
. Evaluation for compliance with applicable effluent standards, water
quality standards and management practices
. Consideration of effects on the enhancement, preservation or develop-
ment of historic, scenic and recreational values
. Effects on wild and scenic rivers
. Interference with adjacent properties or water resource projects
. Impacts on navigation
. Compliance with state coastal zone management programs
. Evaluation of potential Impact to marine sanctuaries
. Consistency with state, regional or local land use classifications,
determinations or policies
. Effects on flood losses, Impact of floods, human health, safety and
welfare and the natural and beneficial values served by flood plains
Source of Information: 33 CFR 320.4 and 323
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The EPA's responsibilities under Section 404 1n conjunction with the
COE include:
. development of criteria for evaluating locations for discharge of
dredged material under 404(b)(l),
. ultimate authority to veto permits on environmental grounds under
404(b)(l),
. the designation of geographic areas and ecosystems where EPA will
make final determinations on permit applications,
. assistance to states in developing responsibility for delegated
programs,
. determination of boundaries of navigable waters, and
. the authority to halt illegal discharges.
Guidelines developed by EPA in reviewing Corps 404 permit applications
are presented in Table 4.1-3. Where the EPA denies authorization for
dredge and fill activities, the Corps' application will, 1n turn, be
denied. This holds true, too, for other required federal, state or local
dredge and fill authorization.
A federal rule is being proposed by the U.S. Army Corp of Engineers
which would amend policies and procedures associated with certain nation-
wide federal permits for activities 1n waters of the United States
(Federal Register, March 29, 1984). Where permitted by the NPDES
program, outfall structures will be permitted by the Corps of Engineers
under the proposed rule. However, the Corps' district or division
engineer must make a determination that the individual and cumulative
adverse impacts are minimal (Section 330.5(a)(7) of the proposed rule)
following notification by the applicant to the Corps that the outfall 1s
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TABLE 4.1-3
SUMMARY OF EPA CRITERIA FOR APPROVAL OF DREDGED OR FILL MATERIAL
DISCHARGE UNDER SECTION 404(b)(l) OF THE CLEAN WATER ACT
. Where practicable alternatives exist with less adverse Impacts on
the aquatic ecosystem and no other significant adverse Impacts; such
alternatives Include:
- activities resulting 1n no discharge
- alternative discharge locations;
. If water quality standards would be violated;
. If toxic effluent standards would be violated;
. If the continued existence of endangered species would be violated;
. Where requirements to protect marine sanctuaries would be violated;
. Unless considerations of the economic Impacts on navigations are
overriding, where there are
- significant adverse effects on human health or welfare, munici-
pal water supplies, plankton, fish, shellfish, wildlife and spe-
cial aquatic sites
- significant adverse effects on aquatic life and other aquatic-
dependent wildlife
- significant adverse effects on aquatic ecosystem diversity
productivity and stability
- significant adverse effects on recreational, aesthetic and
economic values;
. Specific procedures for making these determinations have been set
forth 1n Subparts C-F of 40 CFR 230.
Source of Information: 40 CFR 230
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being planned. The Corps' district or division engineer can impose con-
ditions or supplementary requirements in association with 404(b)(l) or
other federal guidelines. No permit will be granted which includes, the
alteration of wetlands identified as "important" unless the district
engineer concludes that benefits would outweigh damages. Seven general
categories to define "important" wetlands are listed 1n the Federal
Register (July 22, 1982):
. wetlands having significant biological functions (e.g. food chain
production, species resting, and spawning),
. wetlands set-aside for studies or as sanctuaries or refuges,
. wetlands whose alteration would affect drainage, sedimentation or
salinity patterns,
. wetlands at barrier islands, reefs and bars which shield other
areas from waves, storms and other activities resulting in ero-
sion and other types of damage,
. wetlands that are valuable water storage areas,
. wetlands that are prime groundwater recharge areas, and
. wetlands which provide significant and necessary purification of
incoming waters.
4.1.5 Fish and Wildlife Coordination
The Fish and Wildlife Coordination Act (the Act), PL 85-624 as
amended by PL 89-72, was established with the general purpose of
requiring that fish and wildlife receive consideration in water resource
development activities. The Act states that whenever a department or
agency proposes an activity which will impound, divert, control or modify
a body of water for any purpose, the FWS must be consulted. The FWS
reviews a proposed activity for potential damage to wildlife and makes
recommendations for measures to mitigate or compensate for damage,
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Including consideration of whether alternative, non-wetland sites are
available. This 1s applicable to Section 404 review of a dredge and fill
permit applications, for wastewater disposal activities, and NPDES permit
application review. The PUS 1s also authorized under the Act to conduct
Investigations 1n order to determine the effects of domestic sewage on
wildlife and to report the results of the Investigations to Congress.
Most of the FWS review responsibilities are focused on Section 404
permit applications. However, several aspects of wastewater management
1n wetlands have also drawn the concern of the FWS. These concerns pri-
marily relate to:
. wildlife habitat alterations, e.g., water quality degradation,
and
. accelerated eutrophlcatlon and vegetatlonal changes.
In addition to FWS review responsibilities under the Act, a proposed
wetlands discharge project 1n a coastal area 1s also subject to NPDES and
Section 404 permit review by the National Marine Fisheries Service
(NMFS). Criteria used by NMFS in reviewing Corps' 404 permit applica-
tions are listed 1n Table 4.1-4. NMFS, through the authority of the
Coastal Management Act, provides reports to Congress on the status of the
U.S. shellfish Industries. These reports discuss the relationship be-
tween water quality and the shellfish Industry, the array of Issues
facing this Industry, and state and federal responsibilities 1n shellfish
producing waters.
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TABLE 4.1-4
NATIONAL MARINE FISHERIES SERVICE GUIDELINES
FOR ASSESSING WETLAND ALTERATION
The extent of precedent setting and existing OP potential cumula-
tive Impacts of similar or other developments 1n the project
area;
The extent to which the activity would directly affect the pro-
duction of fishery resources (e.g., dredging, filling marshland,
reduced access, etc.);
The extent to which the activity would Indirectly affect the
production of fishery resources (e.g., alteration of circulation,
salinity regimes and detrital export);
The extent of any adverse Impact that can be avoided through
project modification or other safeguards (e.g., piers in lieu of
channel dredging);
The extent of alteration sites available to reduce unavoidable
project impacts;
The extent to which the activity requires a waterfront location
if dredging or filling wetlands is Involved;
The extent to which mitigation 1s possible to offset unavoidable
habitat losses associated with a water-dependent project that
clearly is in the public Interest.
Source of Information: National Marine Fisheries Service. 1983.
Guidelines and criteria for proposed wetland
alterations 1n the southeast region of the U.S.
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The Federal Endangered Species Act of 1973 was amended in 1978 to
direct the Secretary of the Interior and the Secretary of Commerce to
develop plans for the protection of federally-listed endangered or
threatened species. The Secretary of the Interior, acting through the
FWS, has broad authority to protect and conserve all forms of flora and
fauna considered to be in danger of extinction. The Secretary of
Commerce, acting through NMFS, has similar power to protect and conserve
most marine life.
4.1.6 National Shellfish Sanitation Program
The National Shellfish Sanitation Program (NSSP) evolved in 1925
because of a recognized need for state and federal cooperation in the
protection of shellfish waters. It is a cooperative control program in
which the Public Health Services' Shellfish Sanitation Branch exercises
supervision over the sanitary quality of shellfish shipped in interstate
commerce.
These supervisory duties are outlined in Part I of the NSSP, Manual
of Operations, Sanitation of Shellfish Growing Areas. The manual itself
is intended solely as a guide for states in exercising sanitary super-
vision over shellfish growing, relaying, purification, and in issuing
certificates to shellfish shippers. Part I of the manual develops proce-
dures which are intended as a guide to states in the preparation of their
individual shellfish sanitation laws and regulations and for the sanitary
control of the growing, relaying and purification of shellfish. In addi-
tion, the Public Health Service uses the manual to determine whether a
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state's proposed shellfish sanitation program qualifies for endorsement
by the Public Health Services' National Shellfish Certification Program.
The federal government's role in the protection of state-owned
shellfish waters, therefore, is purely advisory. The NSSP guides the
states in setting up shellfish protection programs. Policies or programs
that would, for instance, regulate placement of an outfall in relation to
shellfish areas are developed at the state level.
The following procedures were outlined by the Shellfish Sanitation
Branch in Part I of the Operations Manual. These procedures must be
adopted at the state level prior to federal certification of their
shellfish protection program:
. adopt adequate laws and regulations for sanitary control of
shellfish industry,
. make periodical sanitary and bacteriological surveys of growing
areas,
. delineate and patrol areas where harvest is restricted,
. inspect shellfish plants,
. conduct inspections, laboratory Investigations and control
measures necessary to insure that shellfish have been grown, har-
vested and processed in a sanitary manner, and
. issue certificates to shellfish dealers complying with sanitary
standards and forward copies to the Public Health Service.
The part played by the Public Health Service involves the following:
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. annually review state's control program Including Inspection of a
representative number of shellfish-processing plants,
. endorse or withhold endorsement of states' control program, and
. publish a semi-monthly 11st of all valid Interstate shellfish
shipper certificates.
Federal supervision of state shellfish sanitary program development
based on the above state procedures can, 1f adopted, have a significant
Impact on the placement of outfalls 1n saltwater wetlands.
4.2 STATE PROGRAMS
4.2.1 Alabama
4.2.1.1 Water Quality Standards
The Alabama Department of Envrionmental Management (ADEN), has
established seven water use classifications that are applied to all state
waters. The definitions for these seven classes would not limit their
application to saltwater areas; however, none of the classes are directed
specifically toward saltwater bodies. Class C—shellfish harvesting
would apparently include saltwater bodies. Table 4.1-1 lists the seven
water use classifications for the state.
General, minimum standards applicable to all state waters include
limitations on settleable solids, floating debris, oil, grease and other
materials, and toxic or harmful concentrations of sewage, industrial or
other wastes. Specific water quality criteria have been developed for
each of the seven use classifications. These criteria Include specifica-
tions for allowable sewage, Industrial and other wastes, pH, temperature,
dissolved oxygen, toxic substances, taste and odor, bacteria, radioac-
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tivity and turbidity. The criteria may differ for each class, but 1n all
cases, have been designed to Insure continued use of the waters for the
designated purpose. 'Shellfish harvesting waters must meet standards
similar to swimming and public water supply. They must also meet the
guidelines of the National Shellfish Sanitation Program (ADEM
Regulations, 1981).
ADEM does recognize that natural waters may have characteristics
outside the limits established 1n the water quality criteria. The
specific criteria for each of the seven use categories set forth
allowable variations for coastal waters, estuaries and tidal tributaries.
These allowances apply to pH and dissolved oxygen. There 1s also a
fairly broad allowance for recognition of natural turbidity levels (ADEM
Regulations, 1981).
To date, the state has not developed a working definition of where
coastal waters stop and coastal wetlands begin, and no distinction is
made between open waters and wetlands in assigning use classifications
(personal communication). Therefore, the water quality standards for
adjacent waters would also apply to wetland areas (personal
communication).
4.2.1.2 Discharge Permits
The state also does not distinguish wetlands from other waters of
the state for the purpose of permitting wastewater discharges. Specific
procedures and guidelines have not been developed for establishing waste-
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load allocations and effluent limitations for wetland discharges.
Generally, permit limits for Industrial discharges to wetlands are deve-
loped from EPA (BAT/BCT) guidelines. In the absence of EPA guidelines,
best engineering judgement Is used. Secondary treatment provides the
Initial bases for municipal discharge limits. In all cases, an analysis
of water use and flow characteristics of the receiving waters are used
for determining any higher degree of treatment required.
4.2.1.3 Construction Grants Program
Projects proposing to discharge to saltwater wetlands would be con-
sidered eligible for funding under the Construction Grant Program. Since
saltwater wetland discharge projects have not yet been funded 1n the
state guidelines Indicating what portions of the project are fundable
have not been established. If a saltwater project were proposed, 1t
would be prioritized 1n the same manner as other projects (personal
communication).
Permitted freshwater wetland discharges have not been considered to
be Innovative or alternative projects and have not received any special
funding considerations. In any case, other than the monies set aside for
funding Innovative and alternative technology, Alabama would not have any
additional funds available for I&A Projects.
4.2.1.4 Other Programs
The legislature of Alabama through the passage of the Alabama
Coastal Area Act established the Alabama Coastal Area Board as an inde-
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pendent state agency with the charter to preserve, protect, develop, and
where possible, to restore and enhance the natural, cultural, historic,
aesthetic, commercial, Industrial and recreational resources of the
state's coastal area (Coastal Area Management Program, 1979). In order
to carry out these responsibilities the legislature provided the coastal
board with the power to develop a management program, adopt necessary
rules and regulations and to review all uses requiring state permits for
compliance with the coastal management program. No state agency can
grant a permit for any activity or action within the coastal area until
the board determines that the permit would be in compliance with the
coastal management program. This permit review authority would apply to
uses which contribute to a waste discharge; uses which alter or destroy
wetlands; and point and non-point wastewater discharges. Based on this
authority, an NPDES permit for a saltwater wetland discharge 1n Alabama
would need to be reviewed and approved by the coastal board.
4.2.2 Florida
4.2.2.1 Hater Quality Standards
Specific classifications or water quality standards have not been
developed by the Florida Department of Environmental Regulations (DER)
for saltwater areas (see Table 4.1-1). However, the state has designated
five water classifications: I, potable water supplies; II, shellfish
propagation or harvesting; III, recreation, propagation and maintenance
of a healthy, well-balanced population of fish and wildlife; IV, agri-
cultural water supplies; and V, navigation, utility and Industrial use.
All of these classifications could theoretically be applied to saltwater
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areas. For each of the classifications there 1s an extensive and
detailed 11st of water quality criteria addressing such parameters as
floating solids, oil and grease, settleable solids, alkalinity, metals,
bacterial quality, dissolved oxygen, nutrients, pesticides, toxics, pH
and transparency.
These classifications and standards apply to coastal waters which
extend from the three-fathom (18-foot) bottom contour landward to the
limit of submerged marine species. Certain saltwater wetlands would be
considered coastal waters under this definition. Other saltwater
wetlands not considered coastal waters but contiguous to coastal waters
would still be considered a part of that water body and possess the same
water quality standards.
Florida DER recognizes that certain portions of waters of the state
(particularly wetlands) do not meet sepdflc water quality standards due
to man-induced or natural causes. The parameters most likely to vary
from the standards in wetland areas are pH and dissolved oxygen.
Alternative water quality criteria may be applied based on designated
water use, extent of biota adaptions to background conditions, evidence
of ecological stress and adverse Impacts to adjoining waters (FAC
17-3.031). Site-specific alternative criteria offer permanent relief
under a given set of background conditions.
Exemptions to specific water quality criteria are also granted for
the experimental use of wetlands for low-energy wastewater recycling.
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Under Section 17-4.243 (4) FAC (Exemptions from Water Quality Criteria),
exemptions from certain criteria may be granted upon petition indicating
that the appropriate criteria will not adversely affect public health or
adversely impact the biological community in the receiving waters or the
contiguous water body. With this exemption, appropirate criteria are not
necessarily the background levels. In addition, an exemption has to be
renewed every five years based on long-term monitoring data, whereas
alternative criteria (Section 7-3.031 FAC) provided experiments designed
to lead to the development of new information concerning wastewater
disposal to wetlands.
4.2.2.2 Discharge Permits
Under Florida state law, coastal wetlands would be considered waters
of the state to the landward extent of specific submerged marine species.
Therefore, any discharge to these areas must receive an NPDES permit.
Although isolated wetlands may not be considered waters of the state, it
is likely that coastal wetlands would not be isolated from other water
bodies. Florida is the only state in the study area which has not been
granted full authority from EPA to administer the NPDES permit program.
The capacity wetlands have to assimilate nutrients, organics and
metals is site-specific and primarily dependent on hydrologic regimes.
Standard water quality models are not generally applicable to wetlands
and as a result, DER has not used predictive models to determine possible
Impacts of discharges to wetlands. In Instances where ambient conditions
warrant site-specific criteria or exemptions, baseline water quality
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studies are used to determine the appropriate criteria. If a standard
wasteload allocation model 1s used and It calls for unusually high levels
of treatment, a blolgical assessment 1s made. The assessment addresses
the relationships between current discharges and detectable problems.
This approach would be limited for proposed new wetland discharges unless
an existing discharge to a comparable wetland system Is available for
observation.
Additional requirements concerning loading rates and treatment
levels have been applied to freshwater wetland discharges. Hydraulic
loading rates are usually restricted to 0.5 to 1.0 inch per week.
Minimum treatment required would be secondary treatment (Chapter 17-6,
FAC) followed by disinfection and storage 1n a holding pond (with a
detention time of three days at design flow) to achieve dechlorination.
Nitrification before discharge would be necessary to optimize nitrogen
removal in wetlands where the ambient pH level is not conducive for
nitrification. Pretreatment to remove phosphorus would also be necessary
for flow-through wetlands unless site-specific information 1s available
to Indicate long-term storage by the wetland sediments. These above
requirements can be modified based on consideration of the type and
ambient water quality of the downstream water body. In addition, some
form of legal control of the wetland would be necessary 1n order to
restrict public access to the site. Current Florida DER philosophy 1s
not to allow discharges to saltwater wetlands because of their environ-
mental value.
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4.2.2.3 Construction Grants Program
The procedure for funding projects under the Construction Grants
Program would not differ significantly for projects In Florida proposing
to discharge to saltwater wetlands if discharges could obtain a discharge
permit. Such projects with a discharge permit would be considered fun-
dable under the 201 Program and they would be placed on the funding
priority list in the same way as other projects.
Florida has not yet addressed the question of status for saltwater
wetland discharge projects as an innovative and alternative technology.
If a project were found to be innovative or alternative, it would be
given a small multiplier in the priority formula which could place it
slightly higher on the funding list. Otherwise, there would be no pre-
ference given an I&A project.
4.2.2.4 Other Programs
Florida has the most extensive coastal area regulatory program of
any of the six states. There are two state dredge and fill programs
under separate statutory authority; the Development of Regional Impact
(DRI) Program for large-scale projects; and two separate coastal permit
programs. A review of these program requirements, however, indicates
that they may not directly apply to wastewater discharges. As in other
states, if modification of the wetland were undertaken, then provisions
of the dredge and fill permitting programs would apply. Permits under
the state's coastal management program could be required for the siting
and construction of treatment facilities but not for a discharge.
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4.2.3 Georgia
4.2.3.1 Water Quality Standards
Georgia has not established specific water quality classifications
for saltwater areas (see Table 4.1-1). Nine general water quality
classes have been developed for classifying all waters of the state,
Including "coastal waters". There is no specific classification for
shellfish harvesting or propagation. However, within the classification
for propagation of fish, shellfish, game or other aquatic life, there are
designated shellfish harvesting areas which must meet the guidelines of
the National Shellfish Sanitation Program.
The Georgia Environmental Protection Division (EPD) does not have an
official policy concerning the discharge of treated wastewater to
wetlands. EPD does not distinguish saltwater wetlands from coastal
waters, therefore the water quality standards given for the adjacent
coastal waters would apply to the wetland (personal communication). The
state's water quality regulations do, however, recognize that certain
natural waters of the state may have a quality that will not be within
the standards specified. Although no specific level of variation is
recognized, this flexibility should be considered in evaluating
wastewater discharges to saltwater wetlands.
4.2.3.2 Discharge Permits
NPDES permits are required for wastewater discharges to wetlands and
the permit process is the same as for other wastewater discharges.
Permit requirements are based on federal effluent guidelines, secondary
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treatment, or some degree of treatment more stringent than secondary
where it is necessary to achieve and/or maintain the water quality stan-
dards. The Georgia EPD does not use predictive modelling to establish
effluent limitations for wetland discharges, but instead, relies on site
analyses and qualitative judgments. If a definable channel exists, the
discharge might be modelled, but in this case, it would not be considered
a wetland discharge.
The Georgia EPD does not have a specific policy in funding of proj-
ects which would propose to discharge to saltwater wetlands. The deci-
sion would apparently be made on a case-by-case basis by the Division
Director. If funding were approved, the project would be placed on the
priority list using the same procedures as for any other project.
Wetland discharges would not likely be considered innovative. This
would be based on the treatment technique more than the type of disposal
proposed. The decision as to whether a project were alternative would be
based on a case-by-case review. EPD would not consider saltwater wetland
discharge projects to be alternative on a blanket basis (personal
communication).
Projects in Georgia with Innovative and alternative technologies are
funded from monies set aside for I&A technologies on the state's general
priority 11st. The priority system does have special provisions for pro-
jects using innovative and alternative technologies.
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4.2.3.3 Other Programs
The Georgia Coastal Marshlands Protection Act was passed by the
Georgia Assembly 1n 1970 to Insure that Georgia's coastal marshlands were
used 1n the public Interest for the benefit of all citizens of Georgia.
The Act Includes a requirement to obtain a permit for most activities and
construction of structures that alter any marshland 1n the state. The
permit review and approval requirements of the Act provide an exception
for construction, maintenance and repair of approved water and sewer
lines. However, the regulations under the Act also Identify depositing
of waste material 1n marshlands as contrary to the public interest.
Lagoons and impoundments for waste treatment located in marshlands are
also identified as contrary to the public Interest. Thus, discharges to
coastal wetlands may be subject to the Act.
4.2.4 Mississippi
4.2.4.1 Hater Quality Standards
The Mississippi Department of Natural Resources (DNR), Bureau of
Pollution Control has established water quality standards for two
classifications which are applicable to saltwater. These two classifica-
tions are Shellfish Harvesting Areas and Fish and Wildlife. Specific
standards have been established for bacteria under Shellfish Harvesting
Areas, and under Fish and Wildlife for bacteria, specific conductance,
dissolved solids and phenolic compounds. Waters which are classified for
shellfish propagation also must meet the requirements set forth in the
latest addition of the National Shellfish Sanitation Program, Manual of
Operations. The relative proximity of a bacterlally-related discharge to
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a shellfish harvesting bed will be considered by the Permit Board prior
to acceptance of that site for disposal. All of the states' water use
classifications are listed on Table 4.1-1.
In addition to standards specific to these classifications, DNR has
also established minimum conditions applicable to all waters. These
standards require that water be free from settleable solids, floating
debris, oil or scum, materials creating color, odor or other nuisance
problems and harmful or toxic substances. Also, municipal, industrial
and other wastes are required to receive treatment or control in accord-
ance with Sections 301, 306 and 307 of the Clean Water Act. Minimum tem-
perature, pH and dissolved oxygen standards are also given and are
applicable to all waters.
The state does not differentiate between saltwater wetlands and
other coastal waters for the purpose of determining appropriate water
quality standards. The water quality classifications and standards
develped by DNR apply to saltwater wetland areas as long as those areas
can be classified as waters of the state. A state water body is any
water within the jurisdiction of the state except for those which are
totally landlocked and privately owned. However, exceptions can be made
to the standard water quality criteria for certain state waters that do
not fall within established limitations due to natural background con-
ditions or Irrevocable man-Induced conditions.
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4.2.4.2 Discharge Permits
Mississippi was delegated the authority to administer its own pollu-
tion discharge permit program (NPDES Program) by EPA 1n 1974.
Mississippi has developed a specialized analysis for determining the
wasteload allocation to wetland areas since the application of standard
steady-state river models resulted 1n requirements for extremely high
levels of treatment. This specialized analysis involves qualitative eva-
luations and other site-specific assessments deemed necessary including
water quality and eutrophication studies.
4.2.4.3 Construction Grants Program
The State of Mississippi has established a priority system for allo-
cation of funds for projects under the 201 Construction Grants Program.
Projects which propose a discharge to wetland areas are considered fund-
able. However, since no saltwater wetlands discharge projects have been
funded as yet, guidelines indicating fundable project portions have not
been established. No special consideration is given to wetlands
discharge projects based on the fact that the receiving water body 1s a
wetland. The project may, however, rate higher on the priority list due
to other factors such as existence of sensitive environmental areas
(e.g., shellfish beds). Projects proposing discharge to wetland areas
have not, in the past, been considered either alternative or innovative
and would, therefore, not be eligible for I&A funding.
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4.2.4.4 Other Programs
The Mississippi Coastal Program based largely on the Mississippi
Coastal Wetlands Protection Law (49-27-1 through 49-27-69, Mississippi
Code of 1972) and the Mississippi Bureau of Marine Resources Enabling
Legislation (57-15-1 through 57-15-17) establishes a set of management
goals for the coastal area which comprises the state's coastal area
policy.
The Coastal Program requires that certain regulated activities
secure a permit prior to conducting that activity, based on the Coastal
Wetlands Protection Law. Two activities which are subject to the coastal
program if they occur in wetland areas are effluent discharges and dredge
and fill activities. If the construction of a sewer system is conducted
or supported by state or federal agencies 1n the coastal area, this is
also subject to the Coastal Program's permit procedure.
4.2.5 North Carolina
4.2.5.1 Water Quality Standards
North Carolina has established a two-part water quality classifica-
tion system with a separate group of classifications and specific stan-
dards for tidal saltwater areas. All tidal saltwater classes must meet
similar standards for chlorophyll a., total dissolved gasses, turbidity,
heavy metals, pesticides, phosphorus, PCB's and radioactive substances.
Specific classifications must meet further standards for floating solids,
other wastes, pH, dissolved oxygen, toxic wastes, temperature and coli-
form bacteria.
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The use classification with the most restrictive criteria for tidal
waters is SA, shellfish waters. In addition to standards for tem-
perature, pH, etc., these waters must meet the sanitary and bac-
teriological standards given in the National Shellfish Sanitation
Program Manual of Operations, (PHS, 1965). Waters which meet these stan-
dards may also be used for purposes specified in other use classifica-
tions. These classifications include SB - Primary Recreation and
SC-F1sh1ng and Secondary Recreation (NCAC subchapter 2B, Sections 01 and
02). Table 4.1-1 lists these classifications.
For all three tidewater classifications, a lower dissolved oxygen
standard is permitted for "swamp" waters and the state also provides for
site specific revisions to the dissolved oxygen standard where certain
natural or man-induced conditions warrant (NCAC). This flexibility and
recognition of the different natural conditions present in wetlands could
be important in the use of wetland areas for wastewater management.
North Carolina also designates certain water bodies as nutrient sen-
sitive. In these locations, any increase in nitrogen and phosphorus
levels is stringently limited thus, perhaps hindering any discharges.
4.2.5.2 Discharge Permits
As with the other coastal states 1n Region IV except for Florida,
North Carolina has been delegated the authority by EPA to administer the
pollution discharge permit program. For effluent limited water bodies,
permits would require technology-based treatment levels as a minimum
level of treatment. However, if a water body 1s water quality limited,
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the NPDES permit would require greater than secondary treatment. The
level of treatment required for discharge to such waterbodies is based on
wasteload allocations typically derived by mathematical modeling. North
Carolina normally uses a standard dissolved oxygen model for deriving
wasteload allocations for wetlands. Modifications to the standard
Streeter-Phelps model are used for wetland areas. As appropriate,
effluent limits other than those indicated by these models are often
used.
4.2.5.3 Construction Grants Program
Each state is given responsibility for establishing a priority list
for funding of projects under the 201 Construction Grants program. In
North Carolina, as in most states, a formula incorporating many parame-
ters is used to establish funding priority. In general, the North
Carolina procedure favors projects that are needed to attain water
quality standards and which would serve large populations in areas with
potentially more serious or widespread water quality problems.
In a discussion with state personnel in North Carolina, it was
revealed that projects proposing to discharge effluent to wetland areas
have been approved for funding. These are prioritized on the same basis
as other projects. Discharges to saltwater wetlands would be reviewed in
much greater detail than freshwater wetland discharges, particularly if
the water body in question 1s one which contains commercially Important
shellfish, recreational fisheries and/or critical wildlife habitats
(personal communication).
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The North Carolina Department of Natural Resources and Community
Development would not consider wetland discharge projects to be innova-
tive, although based on a case-by-case review they could be considered
alternative. Other than funds in the four percent of funds set-aside for
innovative and alternative technologies, wetland discharge projects would
not be eligible for any special funds (personal communication).
4.2.5.4 Coastal Environmental Considerations
At the present time the North Carolina Coastal Resources Commission
(CRC), has not adopted regulations or policies that directly govern uti-
lizing saltwater wetlands as part of wastewater systems. In the absence
of such specific guidance on this subject, there is some wording found in
the CRC general use standards that would affect the use of the coastal
wetlands for projects such as this. In 15 NCAC 07H.0208(2)(A), the North
Carolina Department of Natural Resources and Community Development is
required to find "the location, design, and need for development, as well
as the construction activities involved must be consistent with stated
management objective." In addition, the CRC standards in (2)(B) state:
"Before receiving approval for location of a use or development
within these Areas of Environmental Concern (AEC), the permit-
letting authority shall find that no suitable alternative site
or location outside of the AEC exists for the use or develop-
ment and, further, that the applicant has selected a com-
bination of sites and design that will have a minimum adverse
impact upon the productivity and biologic integrity of
coastland marshland, shellfish beds, submerged grass beds,
spawning and nursery areas, important nesting and wintering
sites for waterfowl and wildlife, and important natural erosion
barriers (cypress fringes, marshes, clay soils)."
Also, (2)(E) states "development shall not measurably increase
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siltatlon," and (2)(F) further states "development shall not create
stagnant water bodies." These findings must be made prior to the
issuance of any permit for development in North Carolina salt water
(coastal wetlands). Any questions of potential environmental degradation
would have to be satisfactorily addressed before a wetland wastewater
disposal program could be considered for implementation.
4.2.5.5 Other Programs jn[Jtortji_ Cajroj i na
In addition to the water quality programs described above, there are
other state programs which could affect the implementation of discharges
to saltwater wetlands. These programs include the state dredge and fill
program and the Coastal Area Management Act (CAMA). The use of coastal
wetlands for wastewater management would require permits from the North
Carolina Coastal Resources Commission through the Office of Coastal
Management if excavation, filling, or structures were proposed in any
Coastal Wetlands Areas of Environmental Concern (AEC). The orientation
of these programs, however, is toward development activities. In fact,
there 1s a special exemption under the CAMA program for utility work
including inspection, maintenance and repair of existing water and sewer
lines. This exemption would not apply to new projects. If a treatment
facility were proposed In association with a private development, full
disclosure would be required for the adjacent high-ground development and
CAMA permits issued for that work also (D. Small, personal
communication).
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North Carolina also has a mosquito control program that has been
designated to reduce or eliminate standing water 1n saltwater wetlands.
Any discharge to wetlands from wastewater treatment would have to be
Implemented within the standards of this program.
4.2.6 South Carolina
4.2.6.1 Water Quality Standards
South Carolina's Department of Health and Environmental Control
(DHEC) has established four specific water quality classifications for
tidal saltwater areas. These classifications Include SAA--Outstanding
Resource Waters; SA-- Shell fishing Waters; SB—Primary Recreation Waters;
and SC—Secondary Recreation and Fishing Waters (see Table 4.1-1). In
each of these categories, water must be free from debris, settleable
solids, toxic, corrosive or high temperature substances; and must meet
certain maximum temperature standards. Further specific standards for
dissolved oxygen, col 1form bacteria, pH, temperature and turbidity have
been established for each of the four classes of saltwater. In addition,
no discharge of treated waste 1s permitted In SAA class waters (South
Carolina Regulation 61-68, 1981).
DHEC recognizes that some waters may not be consistent with specific
numeric criteria of a specified use classification because of natural
conditions. The department may develop specific numeric criteria for
these waters. The state also recognizes that waters vary 1n their abi-
lity to assimilate nutrient loadings. Therefore, specific nutrient stan-
dards may be developed on a case-by-case basis.
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DHEC does recognize the distinct differences of wetland waters and
does apend the term swamp to certain water classifications. Specific
water quality standards have not been developed for wetlands, however*
and except for site-specific standards for pH, dissolved oxygen or
nutrients, as mentioned above, it is likely that standards for water
quality in saltwater wetlands would be the same as for the adjacent body
of open water.
4.2.6.2 Discharge Permits
Wetlands are considered waters of the state and therefore any
discharges to wetlands must be permitted by the DHEC. Wetland discharges
are distinguished from other wastewater discharges and DHEC has developed
a specific policy addressing the determination of wasteload allocations.
The adopted policy recognizes the difficulties in defining average water
quality conditions in wetlands and in predicting the assimilative capa-
city of these waters. When specific water quality data are not available
to identify the impact of a wastewater discharge to any swamp waters,
publicly owned treatment works (POTW's) must provide secondary treatment.
Discharges other than from POTW's must provide best available treatment
(BAT) as defined by DHEC. Where a site investigation Indicates that a
mathematical model can adequately describe the impact of a discharge on
the wetland, such a model will be used in setting a wasteload allocation.
4.2.6.3 Construction Grants Program
The procedures in place In South Carolina for prioritizing and
funding construction grants projects may affect the Implementation of
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projects proposing discharge to saltwater wetlands. Wetland discharge
systems are considered fundable by DHEC, and they are ranked on the
funding priority list in a manner similar to other projects.
The priority system used in South Carolina is designed to favor pro-
jects that would eliminate documented water quality problems from high
volume discharges. One of the factors 1n the ranking formula, the water
quality Improvement factor (E Factor) could, 1n certain situations,
encourage saltwater wetland discharges currently having use restrictions
and currently receiving a wastewater discharge. The E Factor establishes
the value of the project due to its impact on improving water quality.
Different factors are assigned based on the type or classification of the
waters which would be improved. The highest E Factor is awarded when the
water quality improvement would eliminate use restrictions to saltwater
estuaries, swamps or salt marshes.
It has not been determined if wetland discharge projects would be
considered Innovative and alternative (I&A) by DHEC. If a project were
found to be I&A 1t would be ranked separately and funded from monies set
aside for Implementing inovative and alternative technologies. Such a
project would receive no other preference.
4.2.6.4 Other Programs
The South Carolina Coastal Council is responsible for administering
the permit requirement of State Act 123 which was enacted by the General
Assembly of South Carolina in 1977. The Act provides for the protection
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and enhancement of the state's coastal resources. The Coastal Council
has direct state authority to deny or issue permits in the critical areas
defined in the Act. These areas include all of the state's saltwater
wetlands.
Under regulations adopted to implement the permit program, the
C'vjnci! coordinates issuance of permits with agencies which regulate the
installation and operation of wastewater treatment facilities, septic
tanks and landfills. Normal maintenance and repair of sewer facilities
are exempted from Council permit requirements as is the discharge of
treated effluent. However, the Council 1s responsible for review and
comment on any discharges. Their concerns would center on possible
wetland degradation which could involve commercially important shellfish,
recreational fisheries and critical wildlife habitats.
The Council has developed certain standards applicable to wastewater
facilities. These state that:
construction of lagoons or impoundments for wastewater treatment
facilities in critical areas shall be denied unless 1t can be
demonstrated that there will be no significant environmental
impacts and no feasible alternative exists,
whenever feasible, construction and design shall be accomplished
so that no effluent will be discharged into areas where shellfish
and other marine resources would be affected,
critical areas, Including coastal waters, tidelands, beaches and
primary ocean front dunes, should be avoided. Unless no feasible
alternative exists, structures other than pipelines and 11ft
stations will not be permitted 1n critical areas, and
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treatment facilities and discharge pipes should be located and
designed so as not to have adverse impacts upon areas of signifi-
cant use.
4.3 MAJOR INSTITUTIONAL ISSUES
Based on this review of the three major wastewater management
programs and the work conducted as part of the Freshwater Wetlands EIS,
several major institutional issues can be identified. The three major
issues are the need for clear direction in wetlands wastewater manage-
ment, the need to clarify regulatory definitions and the need to provide
program specific guidance.
4.3.1 Need for Clear Direction In Wetlands Wastewater Management
The lack of clear EPA direction concerning the use of wetlands for
wastewater management has resulted in considerable confusion. Some
federal programs discourage the use of wetlands for wastewater managment.
Other federal programs actively promote the use of wetlands as a treat-
ment alternative. These differences in approach indicate the need for
EPA to develop and enunciate a coordinated program direction. EPA should
Indicate whether 1t 1s promoting, passively permitting or discouraging
the use of wetlands for wastewater management and within what
constraints. The Clean Water Act and associated regulations need to be
consistently Interpreted and program specific decisions made within the
framework of this Interpretation.
Because of a lack of a clearly established EPA policy in the area of
wastewater management in wetlands, the standards, permitting and grants
programs are not well coordinated and at times Inconsistent with regard
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to wetland discharges. The problems are evident at both the federal and
state level. Because federal programs are largely being delegated to the
states, close coordination between federal and state agencies responsible
for administering wetlands discharges is essential. In addition, better
coordination between federal agencies with wetlands responsibilities will
be necessary if wetlands wastewater management is to be consistent with
the goals and intent of the Clean Water Act.
4.3.2 Need to Clarify Regulatory Definitions
Several issues relate to the Clean Water Act definitions of wetlands
as waters of the U.S. and of wastewater treatment systems. EPA's con-
solidated permit regulations (40 CFR 122.3, May 19, 1980) defined
wetlands as waters of the U.S. These regulations also state that waste
treatment systems (such as ponds and lagoons) are not waters of the U.S.
(except where those waste treatment systems are, or were previously,
waters of tne U.S.). As noted in the regulations, the Act was not
intended to license dischargers to freely use waters of the U.S. as waste
treatment systems. These definitions made clear that treatment systems
created in waters of the U.S. remained waters of the U.S.
On July 21, 1980, the definitions of waters of the U.S. was changed
based on arguments that the definition was too broad. Several industry
petitioners argued that the language of the regulations would require
them to obtain permits for discharges Into existing waste treatment
systems, such as power plant ash ponds, which had been 1n existence for
years and are impounded waters of the U.S. In many cases, EPA had Issued
4-49
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permits for discharges from, not 1nto» these systems. EPA reviewed the
Issue and then suspended the language 1n question based on the
Impoundment-ash pond Issue. The wetlands Issue, as a result, became
unclear. Until such time as the July 21, 1980, suspension 1s revised,
current regulations state that wetlands are waters of the U.S. and waste
treatment systems are not. This could be Interpreted to mean that 1f
wetlands are used for treatment they would lose their status as waters of
the U.S.
Section 301(b)(l)(B) of the Act states that all discharges to waters
of the U.S. shall achieve a minimum of secondary treatment. Further,
Section 402(a)(l) of the Act states that the requirements of Sections
301, 302, 306, 307 and 308 of the Act must be met before a discharge to
waters of the U.S. can be permitted. None of these citations specifi-
cally addresses wetlands being used for treatment of wastewater. The
current definition of waters of the U.S. (with the July 21, 1980,
suspension) could, therefore, be Interpreted to mean that if waters of
the U.S. are used for treatment, then secondary treatment would not be
required nor must water quality standards be met. However, 1f wetlands
are considered to provide assimilation and not treatment, secondary
treatment would be required prior to discharge to wetlands.
Clarification of the regulations to address this Issue appears
warranted. Stemming from the current definition of wetlands as waters of
the U.S., several important wetland/wastewater management questions
arise. These questions include the following: (1) Can wetlands be used
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to provide treatment? (2) Must control of the wetland be demonstrated by
the discharger? (3) Where must water quality standards be met? (4)
Where will the discharge be permitted? and (5) What components of the
system are eligible for federal grant assistance (and at what level)?
The lack of state regulatory definitions of a wetland as compared to
an estuary or to marine waters could also result 1n problems if water
quality standards for the wetlands differ from standards for the estuary
or marine waters. If standards for the wetland and the adjoining water
body differ, then a specific boundary between the wetland and the
adjoining water body needs to be defined. Otherwise, the set of stan-
dards (and the corresponding treatment requirements prior to discharge)
that apply for specific discharge locations can not be determined.
4.3.3 Need for Program Specific Guidance
Regulations for EPA's three major wastewater management programs
(Water Quality Standards, NPDES Permitting and Construction Grants) are
designed for facilities discharging to free-flowing streams and rivers,
lakes and estuaries. As a result, program guidelines are usually not
applicable for wetlands wastewater management. Specific standards, per-
mits and grants issues for which program guidelines would prove valuable
are discussed below.
4.3.3.1 Water Quality Standards Program
As noted in the November 8, 1983, Water Quality Standards regula-
tions (40 CFR Part 131), a water quality standard defines the water
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quality goals established for a water body, or portion thereof, by
designating the use or uses to be made of the water and by setting cri-
teria necessary to protect those uses. Water quality standards should,
wherever attainable, provide water quality for the protection and propa-
gation of fish, shellfish and wildlife and for recreation in and on the
water. Standards must also take Into consideration their use and value
for public water supplies and agricultural, Industrial and other purposes
including navigation.
In most states, water quality standards, uses and criteria for
wetlands are those that are established for the adjacent free-flowing
stream segments. Many of the standards criteria designed to protect uses
of the streams are not appropriate for wetlands and some significant
wetland requirements and functions are not addressed by stream standards.
Providing for wetland uses in water quality standards could allow for
more effective protection and use of the resource.
Specific elements of the standards program that should be clarified
to consider wetland wastewater management alternatives Include the
following:
. Wetland uses that are protected by the Clean Water Act,
. Other beneficial wetland uses that could be considered in
establishing standards,
. Narrative or numeric water quality standards criteria to protect
and maintain wetland uses, and
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Procedures that can be applied in establishing use criteria.
Generic and site-specific criteria and variances are approaches
that could be used in establishing use criteria. The establish-
ment of wetland use sub-categories, wetland sub-segments (within
an existing stream segment), creating new wetland segments,
seasonal uses and criteria, and narrative criteria are addi-
tional features that need to be considered.
The scientific basis for the clarification of these elements of the
standards program also have not been developed.
4.3.3.2 NPDES Permit Program
Wastewater discharges from publicly-owned treatment works to waters
of the U.S. must receive a minimum of secondary treatment or treatment
necessary to meet applicable water quality standards. Where a wetland
and its downstream water body have different standards (I.e., the
downstream water body has more stringent discharge requirements than does
the wetland) because of site-specific or generic wetland criteria, it 1s
possible that the wetland could serve to provide additional treatment or
assimilation. In such cases, NPDES permitting should consider this
pollutant removal in determining whether downstream standards are met.
The following are the major permits issues related to wetland
discharge alternatives that should be clarified:
Conditions under which technology-based or water quality-based
effluent limits are appropriate for wetland wastewater management
projects;
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. Techniques to establish water quality-based effluent limits for
wetland alternatives;
. Techniques to determine removals of pollutants In wetlands to
meet downstream standards;
. Guidance addressing the current and potential use of permit con-
ditions to mitigate adverse Impacts or respond to regulatory
requirements; and
. Options for monitoring locations and parameters to document
attainment of established limits and/or standards.
4.3.3.3 Construction Grants Program
Wetlands used for wastewater management involve a range of construc-
tion grants Issues related to the cost effectiveness analysis, ownership
or control requirements, funding eligibility and level of federal
funding. The resolution of many of these questions is related to the
interpretation of the Clean Water Act and associated regulations.
Further, planning aspects of the Construction Grants Program may be
valuable to wastewater management agencies regardless of the availability
of construction grants funding.
For a wetland discharge (regardless of any treatment provided),
control, ability to use or ownership of the wetland must be demonstrated.
Construction Grants 1982 (EPA's most recent publication of guidelines for
the Construction Grants Program) states that a project will be evaluated
to determine if the grantee/applicant has sufficient rights to the pro-
ject land to ensure undisturbed construction and operation of the project
for its useful life. Methods of obtaining these rights Include fee
simple title, easements, ownership of certain rights (e.g., those rights
that could be detrimentally modified by the system), and leasing.
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Questions related to liability, reasonable land costs, the area or extent
of a wetland required, loss of the landowner's rights, applicability of
Section 404 permits for the discharge of dredged and fill material, and
impacts on multiple uses become more complex when privately owned
wetlands are involved. The issue of control or ownership may determine
implementability of the wastewater discharge 1n certain cases. For
example, in North Carolina nearly all coastal wetlands below mean high
water (MHW) would be considered to be owned by the state. Waters below
MHW are used for navigation during high tide. Easements on property
owned by the state are handled by the North Carolina Department of
Administration. Irregularly flooded wetlands, however, can be privately
owned.
If water quality standards in the wetland and downstream water body
are appropriately assigned and if they are different (I.e., the
downstream water body has stricter discharge requirements), the wetland
could serve to provide additional treatment to achieve downstream stan-
dards while standards in the wetland are met. Conversely, if the stan-
dards for the wetland and the downstream water body are the same, further
treatment by the wetland would not be required. Regardless of the degree
of treatment provided by a wetland, recent direction (April 25, 1984)
from Jack E. Ravan, EPA's Assistant Administrator for Water, does provide
guidance on the issue of the eligibility of the purchase of wetlands
under EPA's Construction Grants Program. In response to questions
regarding the eligibility of the purchase of wetlands in a South Carolina
project, it was determined that EPA funding is not available for the
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costs of providing treatment beyond the permitted point of discharge to
the wetland.
The following list summarizes the major construction grants issues
related to wetland discharge alternatives that should be clarified:
The specific factors important in developing and evaluating
wetlands alternatives (i.e., environmental review criteria,
implementability, operability, reliability, flexibility, and
energy requirements) that should be addressed;
Access or control requirements over a wetland used for wastewater
management should be clarified; and
Funding eligibility, funding levels, applicability of IoA, etc.
should be clarified.
4.3.3.4 Other Programs
Other program requirements and wetland protection procedures may
apply to wetland discharges. The extent to which the other programs
discussed in this chapter apply specifically to wastewater management in
wetlands needs to be outlined.
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4.4 LITERATURE CITED
Alabama Water Improvement Commission. 1982. Regulations, policies and
procedures. Title II Water quality criteria and use classifica-
tions. Montgomery, Alabama. 37 pp.
Burke, R. August 1983. Personal communication. Georgia Environmental
Protection Division.
Department of the Army. Office of the Chief of Engineers. 1977. U.S.
Army Corps of Engineers permit program: a guide for applicants.
Washington, D.C. 20 pp.
Department of Defense. Corps of Engineers. Department of the Army.
1975. Permits for activities in navigable waters or ocean waters.
Federal Register 40(144). Washington, D.C. pp. 31320-31428.
Department of Defense. Corps of Engineers. Department of the Army.
1979. Environmental quality: policy and procedures for imple-
menting NEPA (33 CFR Part 230). Preliminary. Federal Register
44(127). Washington, D.C. pp. 38292-38316.
Department of Defense. Corps of Engineers. Department of the Army.
1981. Environmental quality; Policy and procedures for imple-
menting the National Environmental Policy Act (NEPA); Correction (33
CFR Part 230). Federal Register 46(40). Washington, D.C. pp.
14745-14746.
Department of Defense. Corps of Engineers. Department of the Army.
1983. Proposed revisions to rules for dredge and fill permits under
section 404 of Clean Water Act (48 FR 21466). Environment Reporter
14(3). Washington, D.C. pp. 108-118.
Department of Defense. Corps of Engineers. Department of the Army.
1984. Proposed rule to amend permit regulations for controlling
certain activities in waters of the United States. Federal Register
49(62). Washington, D.C. pp 12660-12664.
Department of Defense. Corps of Engineers. Department of the Army.
General regulatory policies; permit authority (33 CRF 320). Code of
Federal Regulations. Washington, D.C. pp. 641-652.
Department of Defense. Department of the Army. 1982. Environmental
quality; environmental effects of Army actions (32 CRF Part 651).
Federal Register 47(192). Washington, D.C. pp 43685- 44562.
Federal Water Pollution Control Act, as Amended (The Clean Water Act).
1972 with 1977 and 1978 Amendments. Water Pollution Control
Federation. Washington, D.C. 136 pp.
4-57
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LITERATURE CITED (continued)
Florida Department of Environmental Regulation. 1981. Florida Statutes.
Chapter 403 Environmental Control, pp. 778-836.
Florida Department of Environmental Regulation. 1981. Florida Statutes.
Title XVIII Public Lands and Property, Chapter 235, State Lands.
pp. 1432-1461.
Florida Department of Environmental Regulation. 1982. Supplement to
Florida Statutes 1981. Chapter 403, Environmental Control, pp.
501-514. Chapter 253, State Lands, p. 307-320.
Florida Department of Environmental Regulation. 1983. F.A.C. Chapter
17.3. Water Quality Standards. Chapter 17-4. Permits.
Garrett, W. 1983. Personal communication. Georgia Environmental
Protection Division.
Georgia Department of Natural Resources. Environmental Protection
Division. July 1980. Water use .classifications, trout stream
designations and water quality standards for the surface waters of
the state of Georgia. 29 pp.
Grant, S.O. Jr. 1983. Personal communication. South Carolina
Department of Health and Environmental Control.
Hell, D. August 1983. Personal communication. Florida Department of
Environmental Regulation.
Johnson, M. August 1983. Personal communication. Georgia
Environmental Protection Division.
Mclndoe, J. August 1983. Personal communication. Alabama Division of
Environmental Management.
Manasco, W. August 1983. Personal communication. Alabama Division of
Environmental Management.
Memorandum of Agreement between Alabama Department of Envrionmental
Management and the Corps of Engineers relating to section 404 and
section 10 permits. July 1983. 3 pp.
Mississippi Department of Natural Resources, Bureau of Pollution Control.
February 1982. Water quality criteria for intrastate, interstate
and coastal waters. Jackson, Mississippi. 15 pp.
National Marine Fisheries Service. 1983. Guidelines for proposed
wetland alternations in the southeast region of the U.S. 13 pp.
4-58
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LITERATURE CITED (continued)
North Carolina Administrative Code. February 1983. Subchapter 7H - State
guidelines for areas of environmental concern. Sections .0100 to
1000. pp.7-1 to 7-59.
North Carolina Department of Natural and Economic Resources.
Environmental Management Commission. 1979. North Carolina
Administrative Code. Chapter 2 Environmental Management.
Subchapter 2B Sections .0100 Procedures for assignment of water
quality standards and .0200 Classifications applicable to surface
waters of North Carolina. Raleigh, North Carolina, pp. 2-12 to
2-37.
Olmstead, R. August 1983. Personal communication. National Shellfish
Sanitary Program.
Robertson, P. August 1983. Personal communication. South Carolina
Department of Health and Environmental Control.
Sansbury, C. July, August 1983. Personal communication. South Carolina
Department of Health and Envrlonmental Control.
Schaenbaum, Thomas J. with Kenneth G. Sillman, research assistant.
November 1976. Coastal planning: the designation and management of
areas of critical environmental concern. A university of North
Carolina Sea Grant College Publication. Raleigh, North Carolina.
31 pp and footnotes.
Seyforth, R. August 1983. Personal communication. Mississippi
Department of Natural Resources.
Small, Daniel. September 1984. Personal Communication. North Carolina
Department of Natural Resources and Community Development.
South Carolina Coastal Council. 1981. Permitting rules and regulations.
Chapter 30 Sections 48-39-10 to 48-39-230. Code of Laws of South
Carolina. 49 pp.
South Carolina Department of Health and Environmental Control. July
1981. Water classification standards system for the state of South
Carolina. Regulation 61-68. 16 pp.
State of Florida Department of Environmental Regulation. 1982. F.A.C.
Chapter 17-25, Regulation of stormwater discharge.
State of Florida Department of Natural Resources. Division of State
Lands. Sovereignty submerged lands management, Rule No. 16Q-21 and
correction sheet.
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LITERATURE CITED (continued)
Sutton, Reg. August 1983. Personal communication. North Carolina
Department of Natural Resources and Community Development.
Thabaraj, J. July 1983. Personal communication. Florida Department of
Environmental Regulation.
U.S. Environmental Protection Agency, February 1983. Region IV Atlanta,
Georgia. Wetlands Disposal of Treated Wastewater Environmental
Impact Statement Phase I Report.
U.S. Fish and Wildlife Service. Fish and Wildlife Coordination (16
U.S.C. 661-667e). pp. 409-415.
Wahab, T.A. 1983. Personal communication. North Carolina Department of
Natural Resources and Community Development.
Westall, F. July, August 1983. Personal communication* North Carolina
Department of Natural Resources and Community Development.
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5.0 SCIENTIFIC CONSIDERATIONS
Saltwater wetlands are characterized by physical
and biotic factors working in dynamic equilibrium.
Key components of these ecosystems Include geomor-
phology, vegetation, hydrology, water quality and
wildlife. The use of saltwater wetlands for muni-
cipal or seafood-processing wastewater management
has the potential for both positive and negative
impact. The purpose of this section is to identify
and describe the major functions and processes of
saltwater wetlands in the southeastern United
States and to identify and assess the known or
expected impacts related to wastewater management
in these wetlands.
The formation of saltwater wetlands and the physical forces that
continue to shape them are discussed in the opening section of this
chapter. The distribution and species composition of wetland vegetation
are dependent on the geomorphology of each wetland. Vegetation forms the
base of the food chain for all organisms associated with this system.
Regional characterization and tidal inundation are two of several factors
discussed concerning the hydrology of wetlands. Water quality, a closely
associated wetland component, is discussed with regard to natural con-
ditions and potential changes resulting from wastewater discharges.
Wildlife characteristic of saltwater wetlands, including threatened and
endangered species, is described as the final saltwater wetland com-
ponent. Scientific factors related to wastewater management in saltwater
wetlands provide the summary section of this chapter.
5-1
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5.1 GEOMQRPHOLOGY
5.1.1 Estuaries
According to the generally-accepted definition of PrUchard (1967),
an estuary 1s a semi-enclosed coastal body of water which has full con-
nection with the open sea and within which sea water 1s measurably
diluted with fresh water derived from land drainage. River mouths,
coastal bays and lagoons behind barrier Islands are examples of
estuaries. In the southeast, estuaries are either the mouths of drowned
river valleys, bays or lagoons semi-Isolated from the sea by barrier
island formation, or some combination of the two. Eighty to ninety per-
cent of the Atlantic and Gulf coasts consist of estuaries and lagoons
(Emery, 1967), the remainder being headlands. Salt marshes are prominent
geomorphlc features of Southeastern estuaries.
The estuaries of today were formed 1n geologically recent (Holocene)
time by the rising sea level which resulted from melting of the 1ce
masses of the last period of global glaciation (Russell, 1967; Figure
5.1-1). Estimates of sea-level rise since the Quarternary Ice Age range
from 450 to 800 feet. Estuarine development reached a peak when a sea-
level still stand was established about 3000 years ago (Russell, 1967;
Figure 5.1-2).
Once formed, estuaries function naturally as traps for terrigenous
sediments discharged by rivers, sediments eroded from the basin margin,
and sediments moving along open beaches or onshore from the Immediate
offshore region (Gullcher, 1967; Mathews et al., 1980; Figure 5.1-3).
5-2
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(D)
(E)
Figure 5.1-1. Development Stages in a Shoreline of Submergence. The
initial stage (A), characterized by headlands projecting
seaward, results from drowning of the lower reaches of
stream valleys. In early youth (B), sea cliffs at the
ends of the headlands are typically present. Depositional
features, such as bayhead beaches and sandspits, are
characteristic of late youth (C). In early maturity (D),
the water between headlands has become somewhat enclosed
by the formation of bayhead bars across the entrance
resulting in the development of lagoons or "lakes."
Continued erosion and filling of the lagoons results in
the formation of a more regular shoreline lying back
of the original headlands; this stage, essentially one
of equilibrium, is termed full maturity. Source: Reid 1961
5-3
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j
i
4
v /EBB-TIDAl
V / r\ft TA
Figure 5.1-2. Generalized Well Developed Estuarine System.
-------
Figure 5.1-3,
Schematic representation of estuarine dynamics
showing river flow moving obliquely towards the
viewer, tidal inlet flow moving obliquely away
from the viewer during flood tide, and lateral
distribution processes acting to disperse
sediment throughout the basin. The enlarged
section illustrates vertical accretion of
suspended material and lateral distribution
of previous deposits by shoreline erosion and
redistribution. Basin sediments accumulate by
positive-filling from rivers, inverse-filling
from the sea by flood tides, and neutral- filling
by self-digested materials eroded from the basin
margin. Source: Rusnak, 1967
5-5
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The existence within an estuary of an essentially closed circulation
system for suspended sediments is due to the character of water movement.
Water passes freely through an estuary yet sediments are trapped or, at
least, are retarded in their movement (Postma, 1967).
Initially, clay-sized material is entrapped. During transport,
these sediments may undergo many changes as a result of chemical or
biological processes, salinity variations, presence or absence of vegeta-
tion, burrowing animals, etc. The process of flocculation and de-
flocculation of sediment particles under the influence of changes In
salinity (resulting from ebbing and flooding tides) exerts a great
influence on the settling velocity of suspended sediments. This process
is conducted at the fresh and salt water interface (Postma, 1967). The
end result of these changes is to increase sufficiently the size of
suspended sediment particles so that settling occurs during slack water.
Sediments in an estuary may be carried back and forth and deposited and
eroded many times before they settle permanently.
Although some estuaries may be sandy, the typical deposits of most
estuaries are fine-grained muds. Gradually, depositional areas of
estuaries may build to such an extent that they become emergent on low
tides and form intertldal flats. After deposition on these flats, sedi-
ment particles may adhere to mud surfaces and require relatively higher
current velocities to resuspend them (Postma, 1967). This results 1n a
net increase In the size of depositional areas over time and the gradual
filling of the estuary over the course of many thousands of years.
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5.1.2 Salt Marsh Ontogeny
Once tidal flats begin to be periodically exposed, they become
potential sites for colonization by emergent vegetation such as Spartlna
or mangroves. The principal factors which Interact to determine the
development of the salt marsh appear to be the tidal range, the phy-
siology of the plants Inhabiting the Intertldal areas, the process of
sedimentation on open tidal flats and within the stands of plants, and
the changing level of the sea relative to the land (Redfleld, 1967).
In a study of a New England salt marsh, Redfleld (1967) hypothesized
that salt marsh development begins when a barren slope near the high-
water level becomes vegetated by plants tolerant of limited submergence
(I.e., high-marsh species), In this case Spartlna patens, dwarf S. alter-
niflora and Distlchlis spicata. As they decompose, these plants produce
what 1s termed high-marsh peat. The Intertidal slope becomes covered
with tall ^ alternlflora. The accumulation of sediment within the ^
alterniflora stand builds up a layer of Intertldal peat until the high-
water level 1s reached. High-marsh species then succeed the Intertidal
species (Redfleld, 1967).
If sea level rises after this process begins, the uplands bordering
the estuary will become submerged and covered with a layer of high-marsh
peat. If sediment 1s deposited in the Intertldal area at a rate as great
as or greater than the rise In sea level, then the Intertldal marsh will
grow out over the rising surface of the Intertldal flat such that the
lower limit of S. alternlflora retains Its critical elevation relative to
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the rising high-water level. Meanwhile, high-marsh peat will be depo-
sited over the 1ntert1dal peat as far Into the estuary as the Intertldal
marsh has built up to the high-water level. Therefore, a well-developed
salt marsh will consist of high-marsh peat (covered with high-marsh
vegetation) which increases In depth from the upland to the site of the
original high water line and will be underlain by the surface of the sub-
merged upland (Figure 5.1-4). Beyond that, the subsurface will usually
consist of sedimentary deposits overlain by Intertldal peat that slopes
upward, away from the upland (Redfleld, 1967). Over many years, the
estuary is transformed into a marsh-filled lagoon (Figure 5.1-2).
5.1.3 Soils
Along the Gulf coast, salt marshes are built primarily upon deltaic-
alluvial deposits created by the major river systems. Those of the south
Atlantic region are built upon soft silt deposits which bridge the
estuarine lagoons between the barrier Islands and the mainland (de la
Cruz, 1981).
Tidal-marsh soils are of Holocene origin and consist of sediment
layers deposited over older, Pleistocene sand layers (Hoyt, 1968). Marsh
sediments are composed of fine sand, clay and organic deposits 1n various
percentages and large amounts of water. These soils are less permeable
than upland soils. There are two layers 1n marsh sediments. The upper
layer 1s aerated, leached and dark brown in color. The lower layer Is
black and rich in reduced compounds resulting from anaerobic decom-
position of organic matter. These compounds are principally, sulfides of
5-8
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UPLAND
HW-
Figure 5.1-4.
Development of a typical New England salt marsh with rising
sea level and continued sedimentation. Source: Redfield,
1967
5-9
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Iron and other metals (Mathews et al., 1980). The pH of this anaerobic
layer is neutral to slightly alkaline.
The combination of constantly water-saturated conditions and the
presence of large amounts of organic soils (hlstosols) make salt marshes
sites of nutrient and metal adsorption. Wastewater from sewage treatment
or shellfish-processing facilities could be a significant source of
nutrient input and, to a lesser extent, metals Input (Section 5.4, Water
Quality).
5.1.3.1 Nutrients in Soils
Besides being sediment traps, estuaries are also physical and biolo-
gical nutrient traps. Nutrient recycling by estuaMne organisms Is
fairly rapid and creates a kind of self-enriching system (Odum, 1971).
This natural tendency toward eutrophlcation makes estuaries vulnerable to
pollution because pollutants are trapped as readily as nutrients.
Nutrients are constantly exchanged between living and nonliving
structural components of the ecosystem In nutrient or blogeochemlcal
cycles. Each of these Interdependent cycles has a relatively small
"exchange pool" that 1s rapidly cycled between organisms and their Imme-
diate environment and a much larger, slow-moving, "reservoir pool" 1n the
atmosphere (nitrogen cycle; Figure 5.1-5) or sediment (phosphorus cycle
Figure 5.1-6).
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Detritus-
microbial
complex
[6]
Ammonia
Marsh
soilN
HI r"" Soil
organic
N
Figure 5.1-5. A model of the marsh nitrogen (N) cycle showing
the major stores of N and interrelated processes,
(Gosselink et al., 1979)
5-11
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MICRO
ORGANISMS
1
1
> "^f-
dissolved
orthophosphate
HIGHER PLANTS
ALQAE
dissolved
organic P '
precipitated Inorganic
phosphate
L
SEDIMENT
aeroble
_FePO4 --.--.- ^^ ^
anaerobic
FeS
sulphide
dead organic P
Figure 5.1-6.
Phosphorus cycle 1n a salt marsh.
Source: Long and Mason, 1983.
5-12
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The most common limiting materials In an ecosystem are carbon
dioxide, which enters directly from the air, and Inorganic nitrogen and
phosphorus, which are taken up through the roots. Research has shown
nitrogen to be the most limiting nutrient 1n a salt marsh (Gosselink et
al., 1979). Phosphorus Is usually the limiting nutrient in freshwater
lakes and streams, and this may also be true of fresh and intermediate
marsh habitats. Nichols's (1983) paper on the capacity of natural
wetlands to remove nutrients from wastewater, it was stated that numerous
wastewater slow-rate application studies (in freshwater areas) had shown
that wastewater P did not move far in the soil but was retained near the
surface. Soluble inorganic phosphate was readily immobilized in soils by
adsorption and precipitation reactions with aluminum (Al), iron (Fe),
calcium (Ca) and clay minerals. Phosphate reactions with Ca occurred
under alkaline conditions, while reactions with Al and Fe predominated in
acid to neutral soils. The chemical and physical adsorption of phosphate
onto the surface of soil minerals is a rapid process, with much of the
adsorption taking place within a few minutes. Other, slower reactions
continue to remove phosphate from solution for periods of several days to
several months (Nichols, 1983).
Because N exists 1n many forms (nitrates, nitrites, nitrogen oxides,
ammonia), the N cycle in wetlands is far more complex than 1s the P cycle
(Figures 5.1-5 and 5.1-6). Denitrificatlon 1s the principal means of N
removal, and denltrificatlon 1s dependent upon the supply of available
organic carbon. In (freshwater) wetland soils maintained under anaerobic
conditions, Nichols (1983) reported that 90 percent of added N03+
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disappeared within a few days, either by denitrification alone or 1n
concert with some other microbial immobilization. Under natural con-
ditions, the rate of N03+ diffusion to the anaerobic portion of the sedi-
ment was often limiting. Nitrification of Nh^. to N03+ took place in the
oxygenated surface layer of the soil. The N03+ then diffused through the
aerobic layer to the anaerobic layer where it was denitrified.
Nichols (1983) further reported that, with increased loading rates,
a wetland's efficiency of N or P removal from wastewater declined. With
continued application, a P-saturation point was eventually reached in the
wetland soil after which P could be released from the soil to the
overlying water, if the water had a relatively lower P content. N remo-
val did not decline over time since the supply of organic carbon,
necessay for denitrification to take place, is virtually inexhaustible in
a wetland. Nichols (1983) concluded that wetland vegetation could absorb
large quantities of N and P during the growing season, but that much of
it was released back to the water column when the plants died and decom-
posed. Additionally, it was concluded that wastewater application to
natural wetlands was an effective method of nutrient removal only if
wetland area was abundant and loading was low (e.g., one hectare of
wetland needed to remove 50 percent of the N and P in wastewater produced
by 60 people). Because higher N and P loading rates would be accompanied
by higher hydraulic loadings, retention times in the marsh would be
reduced and less time would be allowed for N and P removal reactions to
occur. At very high loadings, N and P removal would be restricted to
settling out of particulate forms (Nichols, 1983).
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Den1tr1ficat1on 1s regulated by the supply of organic carbon. Odum
et al. (1979) have hypothesized that specific tidal wetland areas may
either export or Import participate organic carbon on an annual basis
depending upon two geophysical factors: 1) the geomorphology of the
wetland drainage basin and 2) the relative magnitudes of the tidal range
and freshwater Input from upland sources. Odum et al. (1979) stated that
drainage basins connected to large water bodies by a narrow, shallow
channel act as traps for organic material produced In and around the
basin and also for organic matter brought In by Incoming tides. These
drainage basins have a net Import of organic carbon. At the opposite
extreme are V-shaped drainage basins which gradually deepen and widen
toward the mouth. Such basins are net exporters of particulate carbon.
Most estuaries have geomorphologlcal characteristics Intermediate between
these extremes. In such cases, the relative strengths of tidal and fresh-
water Inputs, along with other hydrologlcal considerations, will control
the annual net flux of particulate organic carbon (Odum et al., 1979).
5.1.3.2 Metals 1n Soils
When metals in a dissolved state reach aquatic systems, their beha-
vior 1s governed by the rules of coordination chemistry (complex
formation). Trace metals form associations with water molecules
(hydratlon) or with organic molecules (chelatlon). The activity or mobi-
lization of trace metals 1n aquatic systems 1s Influenced by redox poten-
tial and pH, but activity 1s determined primarily by the stability of the
element-complex (Brooks, 1977).
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Trace metal concentration is divided among the free ionic forms,
inorganic ion pairs, Inorganic and organic complexes, Inorganic and
organic colloids, and living organisms and their remains. The con-
centration of each of these ionic forms changes continually and Is
affected by temperature, salinity, solubility, water hardness, chemical
speciation, biological activity and other factors (Dvorak, 1978).
Within sediments, metals are associated with organic compounds or
clay particles, both of which are abundant in estuarine salt marshes.
Transport mechanisms for metals 1n rivers entering estuaries vary
according to the type of metal transported, the type of substrates
through which the river flows, and the sediment load of the river. Other
components of fluvial matter are humic adds which are known to have
stong metal-chelating capabilities (Dvorak, 1978).
The mobility of metals varies with environmental conditions (Table
5.1-1). In the neutral-to-alkallne, anaerobic soils of salt marshes,
most metals are immobile or have very low mobility. Therefore, metals
tend to accumulate in salt marsh and other estuarine sediments.
5.1.4 Assessment
Despite a salt marsh's geologically ephemeral nature, application of
treated wastewater to salt marshes would have no effect on the formation
of estuaries or the processes which create them. On a human timescale,
however, there appear to be three geomorphologlcally-related areas of
concern: 1) erosion, 2) accumulation of nutrients 1n marsh soils, and
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TABLE 5.1-1
RELATIVE MOBILITIES OF SELECTED METALS IN AQUATIC SYSTEMS3
Relative
mobility
Very high
High
Medium
Low
Very low
to Immobile
Oxidizing
aerobic
In
Cu, N1. Hg,
Cd
Pb
Mn, Cr
Environmental
Add
Zn, Cu, N1, Hg
Cd
Pb, Mn
Cr
conditions
Neutral to
alkaline
Cd
Pb, Mn
Cr, Zn, Cu,
N1, Hg
Reducing
anaerobic
Mn
Cr, Zn, Cu,
N1, Hg, Cd, Pb
Source: Dvorak (1978).
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3) accumulation of metals in marsh soils. All of these concerns would be
manifested after relatively long-term exposure of salt marshes to treated
wastewater and would further contribute to an estuary's natural tendency
toward eutrophication or pollution.
Erosion would be the most immediate and therefore most observable
impact. In relatively sparse high marshes, erosion could be significant
unless wastewater was applied at very low velocities or applied such that
the velocity of water in established flow paths was not significantly
increased. Materials eroded from the high marsh could impact the vegeta-
tion of the low marsh through sedimentation. Denser marshes would pro-
bably be able to sustain higher velocities before erosion took place.
Conversely, nutrient-laden effluent could stimulate high-marsh plant
growth to the extent that sediment eroded from upland areas would be
trapped and deposited in the high-marsh. Over the course of time, the
high-marsh vegetation would be overgrown with upland shrubs and other
non-marsh vegetation, or, in other words, the natural fill1ng-1n of the
estuary could be accelerated.
If the objective of wastewater management is merely disposal, 1t
would probably be sufficient to apply treated wastewater to any area
(high or low marsh) of a wetland. However, 1f the objective 1s addi-
tional treatment, application of wastewater must be restricted to the
high marsh since the low marsh is subject to tidal Inundation at regular
Intervals. Application to low-marsh areas for treatment purposes would
be equivalent to direct discharge Into the estuary since metals, nitrogen
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forms and some phosphates would have Insufficient time to be taken into
the marsh soils or vegetation before the next tidal cycle. Although most
phosphates are readily taken into marsh soils in a few minutes' time,
they stay near the surface where they can be resuspended in the water
column by flooding and ebbing tides or by reworking of the sediments by
salt-marsh invertebrates. Exclusive use of high marshes would restrict
the number of sites where treated wastewater could be applied to those
areas having very extensive high marshes. In many places, however, par-
ticularly 1n the south Atlantic region, the high marsh exists only as a
relatively narrow band surrounding more extensive low marshes.
Additionally, even high marsh is subject to inundation on spring tides or
storm tides. On such occasions, N and P uptake in dead vegetation would
be released to estuarine waters along with any phosphates in the soil
that were over and above the point of saturation.
Gulf coast marshes differ from south Atlantic marshes in several
respects. First, because of higher productivity, more dead material
accumulates in Gulf marshes than in south Atlantic marshes. Secondly,
tides have less Influence on the lateral movement and physical fragmen-
tation of dead material on a day-to-day basis, because tides along the
Gulf have less energy than those along the south Atlantic. Thirdly,
flushing of Gulf marshes occurs in pulses over long periods of time.
Summer southerly winds and storm tides provide the driving force in the
net export of organic material. These factors result in longer exposure
periods and calmer Inundations of marsh areas, both of which facilitate
nutrient deposition (de la Cruz, 1981). For this reason, wastewater
5-19
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application may be more feasible in Gulf coast marshes than in south
Atlantic marshes.
In summation, the geomorphology of marshes 1s such that most cases
of treated wastewater application may need to be restricted to very low
levels of loading on very large surface areas, preferably on Gulf coast
marshes on wide-mouthed estuaries. Even then, however, there are insuf-
ficient data available to determine what constitutes a low-level applica-
tion, how much surface area 1s adequate, and what are the uptake rates of
N and P by salt-marsh vegetation. While analytical tools used to study
estuarine characteristics seem adequate to detect impacts, estuarlne
characteristics (such as the relative strengths of river and tidal flows,
depositional/erosional patterns, sediment budgets, tidal energy, soil
characteristics, nutrient loading, etc.) may vary considerably from one
estuary to the next, necessitating case-by-case baseline or operational
monitoring studies.
5.2 VEGETATION
The major vegetation habitats found in the saltwater wetlands of the
southeastern United States include salt and brackish marshes, mangrove-
swamp forests and submerged aquatic grass beds. Of these, marshes and
mangrove swamps are the habitat types directly relevant to the subject of
wastewater discharges in saltwater wetlands. Aquatic grassbeds are
marine or estuarine subtidal systems and are not defined as a terrestrial
wetland habitat. Intertidal mud flats are often associated with the
edges of marshes, but support no vascular plant communities. Grassbeds
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and intertidal flats, however, may be affected by wastewater runoff
following discharge into wetlands.
5.2.1 Marshes
The largest habitat-type by area found in the southeastern saltwater
wetland environment is the marsh. Marshes are vegetated flats with mini-
mal elevation in areas with a gentle coastal slope and low wave-action
energy. These conditions are most often found in estuarine tidelands,
the landward sides of barrier islands and along intracoastal water bodies
protected by barrier islands.
5.2.1.1 Salt Marsh
Salt marshes are subject to periodic inundation and so the vegeta-
tion of a salt marsh is specifically adapted to this environmental
stress. The salinity values found in a saltmarsh are high but vary with
season and location. Soil salinities of 25 to 42 ppt have been reported
from the Altamaha River delta of Georgia (Gallagher and Re1mold, 1973;
Gallagher et al., 1975), and marsh salinities of about 12 ppt have been
recorded for the Louisiana Chenler Plain (Gossellnk et al., 1979). A
waterlogged, salt tolerant grassland grows under these conditions. This
grassland is divided into low- and high-marsh zones.
The low-marsh zone is the area that extends from the water's edge at
mean sea level inland to the mean high-water level. This area is domi-
nated by smooth cordgrass (Spartina alterniflora). which grows in a tall
form adjacent to the shoreline and In a shorter form at higher eleva-
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tions. The high-marsh zone extends from the mean high-tide level Inland
to the limit of high spring and storm-tide inundation. Without the
stress of regular tidal flooding, the high-marsh zone supports a more
variable plant community dominated by black needlerush (Juncus
roemerianus) and saltmeadow cordgrass (Spartina patens). Saltgrass
(Distichlis spicata), sea oxeye (Borrichia frutescens), saltmarsh aster
(Aster tenuifolius) and smooth cordgrass are also found as associated
species in the high-marsh zone.
In some areas of the high-marsh zone, flats and depressions occur
where saltwater can collect and evaporate. In these salt pannes or salt
barrens, salinity is very high and a number of salt tolerant plants
(halophytes) are found. Saltgrass and the succulent glassworts
(Salicornia spp.) and saltwort (Batis martinima) are dominant 1n these
locations.
As marsh elevation increases, a shift to upland vegetation occurs.
A transitional zone is found, which may contain vegetation typical of a
variety of hydrology and salinity regimes. The shrubs marsh elder (Iva
frutescens). groundsel bush (Baccharis halimifolia) and wax myrtle
(Myrlca cerifera) are typical of this transition area.
The species and distribution of plants 1n a salt marsh are deter-
mined primarily by the depth and regularity of tidal flooding (Chapman,
1938; Hinde, 1954; Adams, 1963). The differing habitat preferences of
smooth cordgrass and saltmeadow cordgrass Illustrate the importance of
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tidal level on vegetation distribution. Smooth cordgrass tolerates regu-
lar, deep saltwater flooding and, as a result, can form pure stands 1n
the lowest saltmarsh zones. In contrast, saltmeadow cordgrass can
tolerate full seawater on occasion but cannot withstand frequent sub-
mergence (O'Nell and Mettee, 1982). Thus, this species 1s found at
higher elevations. Other factors such as soil type, nutrients, tem-
perature, salinity, plant competition and human environmental alteration
are also Important to saltmarsh zonatlon (Penfound, 1952) but are not
preeminent. The limited dominance of salt-tolerant species such as
glassworts, saltworts and saltgrass In high-salInlty salt barrens Is an
example of the localized effect of one such environmental variable.
In a biological sense, succession 1s the change In community struc-
ture from a simple system dominated by abiotic physical factors towards a
system of greater biological diversity, maturity and stability. Each
progressive stage 1n succession Is supported by environmental modifica-
tions caused by pre-existing biological communities.
The vegetative succession 1n salt marshes occurs as a linear gra-
dient away from the marine shoreline toward terrestrial upland. Whether
the saltmarsh plant community 1s capable of modifying Its surrounding
environment over time by substrate deposition and stabilization 1s not
clear. Marsh development may begin with the accumulation of sediment 1n
a seagrass bed, which permits the colonization of smooth cordgrass.
Further tidal sedimentation 1n the smooth cordgrass habitat would then
allow the migration of black needlerush Into the area. Saltgrass and
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saltmeadow cordgrass growth would be the next step 1n a progression to
the ultimate establishment of upland vegetation (Humm, 1973). This
progression Is hypothetical since no experimental evidence or long term
observations are available. It has also been suggested that varying sea
level, rather than biological environmental modification, 1s the dominant
factor In saltmarsh succession (Adams, 1963).
A salt marsh is a pioneer community 1n a hostile physical environ-
ment and so biological diversity is low. Very few plants possess the
adaptions such as salt tolerance, substrate stabilization and resistance
to inundation needed to succeed in a saline wetland.
Although diversity is limited, biological productivity 1n salt
marshes is high. Productivity values for salt marshes vary depending
upon estimation techniques. Productivity values as high as 3773 g dry
wt/m2/yr are cited for smooth cordgrass in coastal marshes of Georgia and
South Carolina (Sandifer et al., 1980). Productivity values of this
magnitude are comparable to those of agricultural lands managed for human
utilization. However, a direct comparison of productivity values for
dissimilar systems may not be appropriate (Humm, 1973).
Only a small part of marsh vegetation Is directly consumed by
wildlife. Most of the plant biomass produced in a marsh enters the
detritus food chain (Odum and de la Cruz, 1967). Many chemical and phy-
sical processes break down marsh vegetation Into smaller pieces that
decomposing fungi, bacteria and microorganisms convert into a form usable
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1n higher food chains. The tidal flushing of this detritus makes the
Interface between marsh, tidal creek and estuary an Important feeding
area for shellfish and flnflsh that utilize detrltal resources.
5.2.1.2 Brackish Marsh
Brackish marshes occur between coastal salt marshes and tidal fresh-
water wetlands and along estuarlne shores where riverine fresh water
mixes with marine salt water. Salinities 1n a brackish marsh range from
about 10 ppt to 0.5 ppt. Vegetation zonatlon 1n brackish marshes 1s not
as well defined as that 1n salt marshes because this habitat 1s a tran-
sitional one where plant species from both salt marsh and freshwater
wetland habitats occur.
The zonatlon 1n a brackish marsh 1s primarily dependent upon sali-
nity and not tidal Inundaton, as In salt marshes (Sandlfer et al.t 1980).
The lower reaches of a brackish marsh are similar 1n appearance to a high
salt marsh. Black needlcrush 1s the dominant plant form, often occurring
1n dense stands, while a border zone of smooth cordgrass grows along
river and stream edges. Other common species 1n this area Include salt-
meadow cordgrass, saltmarsh bulrush (Scirpus robustus) and three-square
bulrush (Scirpus olneyl). In the upper reaches of a brackish marsh,
giant cordgrass (Spartlna cynosuroldes) replaces needlerush as the domi-
nant species. Common freshwater species that are mixed with saltmarsh
species Include sawgrass (Cladlum jamaicense). arrowheads (Sag1ttar1a
spp.), spike rush (EleochaMs spp.), cattails (Typha spp.) and common
cane (Phragmltes austral 1s).
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The ecology of brackish and salt marshes are very similar. Both are
characterized by tidal and estuarine import of sediments and nutrients to
the plant community, a detrital food chain based on high primary produc-
tivity, and the dispersal of this detritus by tidal flushing.
Productivity values for brackish marshes are high, although somewhat
lower than those recorded for salt marshes. Values of 2,800 g dry
wt/m^/yr have been reported (Gosselink et al., 1979).
5.2.1.3 Impacts to Marshes from Wastewater Discharges
The use of marsh habitats for wastewater management would rely upon
the capacity of marsh vegetation to successfully utilize potentially high
nutrient loads. Saltwater marshes have been considered for this use
because of the high productivity of the dense vegetation that Is found
there. Also of importance to any discharge plan is the ability of the
marsh vegetation matrix to physically hold, disperse and process
wastewater discharges as influenced by the regular circulation and
flushing that occur 1n tidal marshlands. A number of investigations have
considered the application of sewage on marsh habitat. It has been
suggested that the preferred utilization of marshes for wastewater mana-
gement would be to provide advanced treatment without altering natural
marsh drainage processes (Gosselink et al., 1974; Rabolals, 1980). The
addition of sewage nutrients has been found to increase the blomass of
marsh vegetation (Haines, 1979; Hardisky et al., 1983). Through nutrient
assimilation by vegetation and sediments a marsh can lower the nutrient
content of water passing through 1t to open water systems. The retention
by experimental salt marsh plots of 80 to 90 percent nitrogen and 91 to
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94 percent phosphorous nutrients applied as sewage sludge during summer
months has been reported (Valiela et al.t 1973). An annual nitrogen
nutrient loading capacity for this system was estimated at 110 g/nr (Teal
and Valiela, 1973). Long-term absorption capacity or year round seasonal
retention were not reported in this case, however. An analysis of
nutrient removal by freshwater wetlands cautions that much of the
nutrient uptake by marsh vegetation is seasonally reversible, with
eutrophication impacts occurring when winter dieback of plants takes
place (Nichols, 1983). Because of this phenomenon and because of lowered
vegetation growth and nutrient uptake in winter months, the discharge of
wastewater should likely be reduced during winter.
Heavy metal uptake by marsh plants also has been reported (Lee et
al., 1976; Giblin et al., 1980). Giblin et al. recorded elevated levels
of cadmium, chromium, copper and zinc in marsh vegetation treated with
sewage sludge. In this investigation marsh sediments retained 20 to 35
percent cadmium, 20 to 50 percent chromium, 60 to 100 percent copper, 55
to 100 percent lead, 80 to 100 percent iron, 55 to 60 percent manganese
and 20 to 45 percent of the zinc added in sewage sludge over a two-year
period. The metal loadings reported in this study were 490
mg/m2 cadmium, 10,300 mg/m2 chromium, 2,010 mg/m2 copper, 110,000
mg/m2 iron, 1,740 mg/2 lead, 1,320 mg/2 manganese and 6,820 mg/2 zinc
over a two-year period.
In a report summarizing 12 years of experimental enrichment of a New
England salt marsh, nutrients were found to be non-toxic to vegetation
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when an annual nitrogen input of 225 g/m2 and phosphorous (PoOc) Input of
135 g/m2 were employed (Vallela et al., 1982). Complex and long-term
alteration in plant community composition have been observed during this
investigation. Oscillating blooms and dieback of smooth cordgrass (a
dominant marsh grass species) followed by surface denudation or replace-
ment with other species such as saltwort, saltgrass or marsh hay
cordgrass have been observed. Under the influence of continued nutrient
enrichment the number of plant species growing 1n the marsh also has
declined. These community changes were not judged by the investigators
to be detrimental to the marsh ecosystem since these effects were simply
shifts in vegetation proportions which could be naturally encountered in
undisturbed salt marsh ecosystems.
Changes in salinity, caused by the application of freshwater sewage
to salt and brackish marshes is another area of concern. In a study of
high-salinity southern California marshes, 1t has been suggested that the
continued addition of freshwater effluent could bring about a shift in
vegetation community composition. Freshwater-marsh species could replace
salt-marsh vegetation 1n areas that normally are hypersaline because of
low freshwater input and high rates of evaporation (Zedler, 1982, 1983).
In the southeastern United States, salt marsh and hypersaline salt
barrens may be found in the vicinity of brackish and freshwater marshes.
High annual rainfall and riverine freshwater Input into estuarlne
wetlands cause this association of saline, brackish and freshwater
marshes. The application of freshwater effluent to salt and brackish
marshes could bring about the growth of vegetation typical of marshes
with lower salinity levels.
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A potentially positive Impact from wastewater discharges to marsh
habitats would be the recovery of hydrologlcally-depleted wetlands. The
regular Input of wastewater Into marshes degraded by diking or canal
drainage could help to reestablish these marshes. Diked areas deprived
of natural tidal flow are habitats that could benefit from managed
wastewater discharge (Zedler, 1982).
5.2.2 Mangrove Swamps
Mangrove swamps are found in coastal areas subject to periodic
flooding with saline or brackish water. The plant species found in a
mangrove swamp are facultative halophytes, tolerant of, but not requiring
a saltwater environment. They are limited to saltwater wetlands because
of the reduced competition from other vegetation. Mangroves possess spe-
cialized root and reproductive structures adapted to inundation and
loose, wet soils. Three species dominate the mangrove community: red
mangrove (Rhizophora mangle), black mangrove (Avlcennia germinans) and
white mangrove (Laguncularia racemosa). Buttonwood (Conocarpus erectus)
1s an associated shrub species found in saltwater swamps but 1s not con-
sidered a true mangrove. In the southeastern United States, red mangrove
and white mangrove are limited to peninsular Florida, while black
mangrove is concentrated in peninsular Florida with scattered occurrences
along the northern coast of the Gulf of Mexico.
Within the swamp-mangrove ecosystem, six community types have been
described (Lugo and Snedaker, 1974). Overwash forests occur on islands
where regular tidal flooding takes place. Fringe forests occur as a
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relatively narrow edge along shorelines that are somewhat higher than
average high tide. Riverine forests are found along estuaMne rivers and
creeks where regular tidal flooding occurs. Very tall mangrove growth
occurs In this community. Basin forests occur In depressions that carry
Inland terrestrial runoff toward the coast. This community type 1s found
near the coastline and is affected by dally tidal flow. Hammock forests
are found on slightly elevated areas with minimal tidal Influence. Scrub
forests are made up of mature yet stunted specimens and occur 1n areas
where substrate and nutrient limitations lead to curtailed growth; these
areas are limited to the flat coastal edge of south Florida.
There has been uncertainty with regard to the zonatlon and suc-
cession of mangrove ecosystems. Early investigations proposed that
mangroves acted as coastline "land builders", exhibiting a linear
zonatlon/succession from coastal pioneer habitat toward upland-
terrestrial tropical forest (Davis, 1940). In a more thorough, recent
presentation, Odum et al. (1982) contend that mangrove populations are
cyclic-climax systems influenced periodically by hurricane, fire or
drought/hypersalinlty. Mangroves were described as being capable of land
maintenance or stabilization but sea level fluctuation was deemed to be
the overriding factor controlling coastline contour. Species zonatlon 1n
mangrove communities is complex, Involving factors of tidal amplitude,
salinity, substrate, interspecific competition and environmental pertur-
bation. A very generalized Interpretation of mangrove growth would place
red mangrove as dominant in the lower elevations between mean low tide
and mean high tide. White and black mangroves, which are very salt
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tolerant, are dominant at higher elevations where evaporation of Infre-
quent tides causes high-salinity conditions. In less saline Inland
areas, buttonwood 1s also found as a component of mangrove communities.
Like salt marshes, mangrove swamps support a substantial detrital
food chain. Branch and leaf Utter are broken down by various physical,
chemical and biological processes. Fine detritus particles are
transported out of the swamp forest by tidal movement. The primary pro-
ductivity of the mangrove ecosystem that supports this detrital food
chain 1s very high, perhaps even higher than that of salt marshes. Odum
et al. (1982) present estimates of mangrove primary productivity as high
as 12.6 grams carbon/m2/day (gC/m2/day). Productivity values expressed
as grams carbon reflects biomass as approximately 30 to 40 percent of dry
weight productivity values.
The feasibility of wastewater discharges has not been Investigated
for mangrove swamps. It 1s possible that mangrove swamps could success-
fully absorb treated wastewater because these swamps are periodically
flushed and very productive. Further investigation of this topic is
needed at this time, however.
5.2.3 Aquatic Grassbeds
Seagrasses are marine flowering plants that form extensive subtidal
beds on sand and clay substrates. Along the coast of Florida, Alabama
and Mississippi three species are commonly found: shoal grass (Halodule
wrightii), turtle grass (Thalassia testudlnum) and manatee grass
5-31
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(Syr1ngod1um fTMfonme). Three species of HalophUa are less commonly
encountered. Widgeon grass (Ruppia marltima) 1s also found as an asso-
ciate of seagrass beds 1n estuarlne areas of lowered salinity. This spe-
cies 1s actually a freshwater plant with marked salinity tolerance. Eel
grass (Zostera marina) 1s a temperate marine species that 1s found along
the Atlantic coast from Canada to North Carolina. Eel grass may occur as
far south as north Florida but 1s not found 1n the Gulf of Mexico.
It has been hypothesized that seagrass habitats are a primary-
successional stage leading to salt-marsh establishment (Humm, 1973) or
perhaps to mangrove swamps. Seagrass beds are highly productive systems;
total community productivity rates of 16 g dry wt/m2/day have been
reported (Zleman, 1982). Seagrass beds may show enhanced production with
moderate sewage-nutrient enrichment but cannot withstand prolonged con-
tact with concentrated wastewater (Zleman, 1982). In such situations,
excess epiphytic algal growth on seagrass leaves, competition with
macroalgae or diminished light penetration, caused by high-nutrient
levels, decreases grassbed coverage.
In brackish to freshwater estuarlne aquatic habitats, a variety of
non-marine submerged flowering plants are found. Fanwort (Cabomba
carolIniana). mares tall (Myrlophyllum spp.), horned pondweed
(ZannlchelUa palustrls), pondweed (Potamogeton spp.), water nymph (Najas
guadalupensls) and the nuisance species, Eurasian water-milfoil
(Hyriophyllum splcatum), are Included 1n this group. Turbidity and
Increased nutrient levels associated with human development and com-
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petition with other species have resulted in diminished grassbed coverage
and community diversity 1n many areas (Zleman, 1982).
5.2.4 Intertldal Flats
Intertldal flats are often found as fringe areas around marsh habi-
tats. Intertldal mud and sand flats occur 1n shallow, open saltwater
areas where tidal fluctuation brings about cyclic exposure and Inun-
dation. These conditions prevent the establishment of vascular plant
communities, but primary productivity from surface algal growth does
occur. The main blotlc feature of this habitat Is a benthlc community
that plays an Important role 1n the detritus food chain of coastal
wetlands.
5.2.5 Summary
The saltwater wetland habitats found 1n the southeastern United
States Include salt and brackish marshes, mangrove swamps, aquatic grass-
beds and Intertldal mud flats. Marshes and mangrove swamps are the
terrestrial wetlands of primary Interest 1n this consideration of
wastewater discharge. Aquatic grassbeds and Intertldal mudflats are
habitats associated with saltwater terrestrial wetlands which may be
affected by wastewater runoff.
Both salt and brackish marshes are highly productive, tldally-
flooded grasslands which support an estuaHne food chain based upon
substantial detritus export. Marsh sediments and vegetation have the
observed ability to absorb sewage nutrients. At the loading rates
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described In experimental studies, no toxic effects on vegetation from
metals or nutrients have been found. Plant productivity has been found
to increase with sewage nutrient applications. However, if wetlands were
mowed to remove increased vegetation blomass, a change 1n species com-
position would be expected. A shift from tall marsh grasses to the
shorter salt grass (Dlstichlis spicata) might cause a concomitant
increase in the mosquito population that prefers salt grass habitat over
other wetland species.
A number of unresolved Issues requiring further investigation
include: the long-term capacity of marsh sediments to absorb nutrients;
the consequences of estuarine eutrophication following nutrient release
by dead, wastewater-fertilized marsh vegetation; the fate of metals
exported from the marsh through physical washout of unabsorbed
wastewater, sediment release, incorporation of metals 1n vegetation
detritus or release from dead vegetation.
Mangrove swamps are comparable to salt and brackish marshes In that
they also are highly productive, detritus exporting systems influenced by
tidal circulation. At this point no experimental findings are available
concerning the discharge of wastewater Into mangrove systems. Seagrass
beds and intertidal mud flats are not suitable for wastewater discharge
since they are aquatic systems with no capacity for effluent retention
and processing.
5.3 HYDROLOGY
Saltwater wetlands are an Integral part of the nearshore and
estuarine ecosystems along the southeastern Atlantic and Gulf coasts.
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Hydrologically, they perform many of the same functions as freshwater
wetlands such as flood storage and storm-flow modification, water-quality
alteration and erosion control. However, another aspect of major Impor-
tance 1s their function as a nutrient source and salinity stabilizer for
estuaries. Consideration of the hydrologic characteristics of these
wetlands is of prime importance in understanding and evaluating their
natural function 1n the ecosystem and the effects of any alterations
caused by utilization as receiving areas for treated wastewater.
Characterization of saltwater wetlands is usually linked to biologi-
cal aspects, such as growth patterns and species present. Most of these
characteristics, however, are related to hydrologic considerations.
Saltwater wetlands within Region IV can generally be divided into two
groups, those occurring along the Atlantic coast of North Carolina, South
Carolina, Georgia, and Florida and those occurring along the Gulf coasts
of Florida, Alabama and Mississippi. This grouping is based primarily
upon the differences in coastal energy, tidal heights and tidal periods
between these two major sections.
Saltwater wetlands, in many respects, have the same hydrologic
characteristics as freshwater wetlands. They are subject to, and
controlled to some extent by climatic fluctuations, morphological vari-
ances, antecedent moisture and infiltration characteristics of their
soils, ground water and man-made Impoundments. To some extent, saltwater
wetlands reduce peak discharges and total storm flow from rivers, reduce
coastal erosion, provide quiescent settling areas for sediment deposi-
tion, and provide filtering and biological transformation of waters
moving through the system.
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5.3.1 Regional Characterization
A general relationship exists between the development of saltwater
wetlands and characteristic coastal energy level. The higher the energy
level, which Is determined by a combination of tide and wave height, the
more extensive the formation of tidal marshes that occurs. Figure 5.3-1
shows the general coastal energy levels for the study area as determined
by comparing average annual tide and wave heights. As can be seen, the
Atlantic coast has a higher overall energy level than the Gulf coast, and
wetland development varies accordingly.
The most developed salt marsh systems 1n the United States are found
along the Atlantic coast areas of South Carolina, Georgia and a small
portion of northern Florida (de la Cruz, 1981). North Carolina's salt-
water wetlands are characteristic of sheltered provinces because of the
extensive offshore barrier islands. Wetlands 1n south Florida are
characterized by localized marshes around waterways and river outlets,
changing to larger mangrove and salt-marsh areas rounding the southern
tip of the state.
Atlantic coastal marshes in the study area were formed on estuarlne
and lagoonal deposits that filled in between barrier islands and the pri-
mary shoreline. These marshes are low and regularly flooded due to the
tidal domination of the coast. Numerous dendritic creeks and deeper
tidal channels develop that have a significant effect on the hydrologlc
characteristic of the marsh. Tides are semidiurnal, and direct inun-
dation by high salinity sea water makes these marshes true salt marshes,
as compared to the more brackish Gulf marshes (de la Cruz, 1981).
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u
HIGH
HIGH
Figure 5.3-1. Coastal Energy Levels. Source: Linton, 1968
-------
Gulf coastal marshes are generally developed upon alluvial deposits
in deltaic formations. They are Irregularly flooded and are low-sal1n1ty
marshes. Tides vary but, generally, they are weak and diurnal. The Gulf
coast is classified as wave dominated because of the relatively lower
tidal rise. The effects of freshwater rivers are greater in these
wetlands than for the south Atlantic coastal wetlands.
5.3.2 Hydro!ogic Budgeting
Hydrologic budgeting is a method whereby an attempt is made to sub-
divide the total movement of water Into and out of an area Into its
various components. Theoretically, the components can be measured and
analysis can then be performed to evaluate the effects of Increasing or
decreasing the individual components. The following can be used to
represent a budget for a saltwater wetland:
P + Qi + 61 + T1 + #S = ET + QoTo + Go
P represents precipitation, Q1 1s fresh surface-water inflow, G1 1s
groundwater inflow, T1 1s tidal Inflow, and As 1s the change 1n storage.
ET represents losses due to evapotranspiration, QoTo 1s combined fresh
surface water and tidal outflow, and Go Is groundwater outflow. Actual
measurement of these components, particularly groundwater flow and tidal
flow, would not be easy. Additionally, groundwater flows may be depen-
dent on tides, in that groundwater levels vary with the tidal cycle and
hence groundwater flow may also vary.
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The greatest effect on the hydrology of saltwater wetlands 1s due to
variations 1n tidal frequency, duration and depth. Surface freshwater
flow Into wetlands may be significant 1n some cases, however, tides domi-
nate over freshwater flow 1n the southeastern Atlantic and Gulf coastal
areas. Generally, wetlands do not provide significant groundwater
recharge (Gresson et al., 1978). Groundwater flow within or out of a
salt marsh 1s difficult to ascertain and must be addressed on a case-by-
case basis. Evapotransplration also may exert a significant effect on
the hydrologic budget of wetlands during some periods of the tidal cycle
and with varying seasons.
5.3.2.1 Precipitation
Precipitation 1s one of the more easily measured quantities 1n the
hydrologic budget. Precipitation values should be considered for speci-
fic sites under consideration for wastewater discharges. Overall preci-
pitation amount varies with season, being generally greater 1n the
winter, and Is generally predictable. Precipitation falling on saltwater
wetlands 1s not Intercepted by vegetation cover because, unlike many
freshwater wetlands, the leaves of most of the vegetation 1n saltwater
wetlands are vertically oriented. Therefore, precipitation 1s not
reduced significantly by Interception, temporary storage or evaporation
from vegetation.
The primary hydrologic effect of direct precipitation is to Increase
soil saturation between tidal Inundations, possibly resulting 1n longer
water retention due to lowered Infiltration capability and loss of
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available storage. Additionally, precipitation may alter surface sali-
nity, pH and add some nutrients to the wetland ecosystem.
5.3.2.2 Surface Water (Fresh)
While water runoff, river Inflow and tidal Inflow are all surface
water phenomena, freshwater inflow and tidal inflow come from two
distinctly separate sources and are unrelated occurrences.
Surface freshwater inflow to a saltwater wetland will vary con-
siderably depending upon the specific site. Great influxes of fresh
water Into an estuary may drastically alter the fresh and saline regimes
which, in turn, may alter the biologic functioning of the estuary. In
this respect, saltwater wetlands act to dampen the surge of freshwater
flooding by providing temporary storage. In addition, greater Increases
in turbidity within the estuary may be avoided by quiescent settling of
flood-carried sediments within the wetland.
In the south Atlantic region, runoff is blmodal, with a large peak
in the spring and a smaller one in late summer. Run-off along the coast
between Cape Remain, South Carolina and Fernandina Beach, Florida varies
from 1 to 5 cubic kilometers per month. Eighty percent of the total flow
can be attributed to the Pee Dee, Cooper-Santee, Savannah and Altamaha
Rivers (Blanton and Atkinson, 1978). Only the Savannah River is con-
sidered to have a major influence on salinity levels 1n the associated
wetlands and estuary (de la Cruz, 1981).
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The Gulf coast wetlands, particularly In the northern coastal area,
are Influenced by freshwater Inflow. Salinity 1s generally lower, 1n the
brackish level of 2 to 15 parts per thousand, due to the Influences of
the Mississippi, Pearl, Pascagoula, B1lox1, Bay St. Louis, Mobile and
Apalachlcola Bay River systems. Influx of fresh surface water varies
seasonally, areally and annually throughout this region.
The discharge volume of rivers emptying Into saltwater wetlands 1s
the primary consideration for estimating the areal extent of Influence on
the wetland area. If the tidal volume 1s greater than the river
discharge, the river Influence will be secondary to tides. This 1s the
case for most wetlands 1n the northern Gulf and southeastern Atlantic
coast. Therefore, while river Influx may cause salinity alterations to
some saltwater wetlands, tidal Influences remain the dominant hydrologlc
effect (Gossellnk et al., 1979).
5.3.2.3 Surface Water (Saline)
By far, the greatest overall hydrologlc effect on most saltwater
wetlands 1s tidally-1nduced saltwater flooding. The range and period of
tidal flooding produces most of the physical and biological charac-
teristics associated with salt marshes and wetlands and 1s the prime
hydrologlcal consideration for evaluating wetlands for wastewater
management.
The south Atlantic region has a semidiurnal tide ranging from less
than 1 to 3 meters and 1s characterized by a few major storm surges.
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Tidal flooding peaks In some wetlands may be delayed from actual coastal
high tides due to the Influence of offshore barrier Islands. This Is
particularly characteristic of wetlands 1n North Carolina.
Tidal amplitudes and flow periods affect the salinity levels and
type of vegetation occurring 1n the 1ntert1dal zone. Flow periods also
govern the frequency of wetland soil saturation and detritus and nutrient
flushing, which would be of concern when considering detention time 1n
wastewater management practices.
Gulf coast tidal variations are more complex than those on the
Atlantic coast. Generally, Gulf tides are diurnal with a range of about
0.3 meters. Sometimes very weak semidiurnal or mixed tides may occur and
tides may be changed In both time and occurrence of highs and lows by
meteorological conditions. These conditions are generally seasonal.
Strong summer winds pile up water along the northern Gulf coast, raising
levels in bayous, bays and canals and frequently Inundating wetlands. In
winter, strong, northerly winds depress the tidal level as low as 0.5
meters below normal, draining marshes for long periods of time (de la
Cruz, 1981). In addition, Gulf coast wetlands are subject to many high-
energy storms 1n June through October that may remove considerable
amounts of detritus and nutrients from the wetlands.
The export of sediment and nutrients to estuaries as the result of
tides varies considerably with season and location. Net export may occur
in summer, winter or during both of these seasons (Smalley and Thlen,
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1976; Ward, 1979; Vallela et al., 1978). Therefore, site-specific stu-
dies would need to be conducted to determine seasonal hydrologlc parame-
ters that may affect the flushing of nutrients from wastewater effluent
Into the estuary.
5.3.2.4 Groundwater
Groundwater also Influences hydrologlc Interactions 1n saltwater
wetlands. However, this aspect of the overall water budget may not be as
significant, compared to river and tidal flows, as it Is for many fresh-
water wetlands. This will have to be determined for each site considered
for a wastewater discharge. Most soils in saltwater wetlands are
comprised of fine clays and organic materials that do not allow for rapid
infiltration of water. The greater the depth of mud and silt, the higher
the Impedance to water transport. This situation can generally be
expected in older marshes.
The overall elevation of a marsh Influences the height of the soil
water table (Chapman, 1974). Therefore, lower marshes will not only be
Inundated more frequently but the soil water table level will occur
closer to the surface. In addition to soil type, the percent of satura-
tion of marsh soil will significantly affect the ability of the soil to
absorb water (allow infiltration) and, consequently, aid in the drainage
of water following inundation. Lower elevation marshes with organic and
clay soil, therefore, would be subject to greater tidal runoff than
higher marshes with more porous soils. This runoff would remove
nutrients and detritus and result 1n pockets of standing water (Chapman,
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1974). These water pockets may have little or no dissolved oxygen, which
enhances anaerobic conditions in the underlying soils and ties up
nutrients so they cannot be used by vegetation. Pathogens remaining in
wastewater applied on the wetlands may also concentrate 1n this standing
water.
Saltwater wetlands usually are not recharge areas for groundwater
aquifers, functioning more often as discharge areas. Groundwater hydro-
logy studies would have to be conducted to determine groundwater flow
patterns for specific wetlands under consideration as receiving areas.
5.3.2.5 Evapotranspiration
Evapotranspiration can be estimated for various densities and types
of vegetative growth by using specific wetland and climatic charac-
teristics, including relative humidity, Insolation, winds, free-water
level, soil saturation depth and water table. Evapotranspiration aids 1n
the removal of wetland standing water formed between tidal cycles, redu-
ces the saturation level of marsh soils thereby Increasing subsequent
storage ability, and 1s a primary reason for soil salinity being above
the salinity of the estuaMne waters. Soil salinity 1s Important because
it affects the type of vegetation that can be grown 1n the marsh soils.
5.3.3 Inundation
The duration, depth and frequency of Inundation 1n saltwater
wetlands are primary factors 1n the distribution of nutrients, removal of
organic detritus and composition of the biota. Inundation Is also a
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prime consideration for the evaluation of a specific wetland as a
discharge site for wastewater, because Inundation frequency, extent and
duration have a great effect on effluent detention time within the
wetland. Inundation 1s usually the result of tidal action, but peak-
flood inundation may periodically occur 1n saltwater wetlands bordering
rivers.
As discussed in Section 5.3.1, inundation frequency varies con-
siderably throughout the study area. South Atlantic wetlands are Inun-
dated more predictably and consistently than Gulf coast wetlands, where
greater variability would be expected.
An understanding of the tidal inundation cycle and its hydrologic
effects within a saltwater wetland is important for evaluating the
possible effects Imposed by the addition of wastewater effluent. Chapman
(1974) detailed the general processes of tidal inflow and outflow from
saltwater marshes. During low tide, tidal waters are absent from the
creeks and channels in the salt marsh. Most of the flow will be remnant
drainage water, freshwater runoff and fresh water from underground
springs, if any. As the tidal Inflow begins, and this may be some hours
after the coastal high tide, lateral seepage may occur from the creeks
and channels Into the marsh soil if the creek level exceeds the ground-
water level. The rate of seepage will depend in large part on the type
of exposed strata, such as sand, clay, mud or peat. In order for seepage
to occur, gases trapped in the soils must be displaced. This does not
readily occur through fine clay and organic soils and, therefore, back
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pressures may limit lateral seepage. Lateral seepage during this stage
of tidal inflow also will be affected by the distance from the creek, the
volume of the creek and the height of the marsh. Once the height of the
tide exceeds the height of the marsh, flooding will occur by sheet flow
across the surface. From this point on, the Increased height of tide
will increase the area of marsh covered and will determine the depth of
flooding within the marsh. Figure 5.3-2 summarizes the various flow
steps during the tidal cycle.
As the tide begins to ebb, the reverse situation occurs. First, the
majority of the surface water departs by way of sheet flow into the
creeks and canals. This carries nutrients out of the marsh and into the
estuary and promotes erosion of the creek banks as water pours over the
edges. Any irregularities in the ground level of the wetland will cause
shallow pools to be left behind. This remaining water is removed by
infiltration and evapotranspiration, as discussed previously. Higher
tide frequency results 1n higher soil saturation levels and longer reten-
tion time for pools.
Following periods of flooding, any infiltration into the marsh soil
causes the water table to rise. The rate of this rise varies with the
distance from drainage creeks and channels and the hydraulic conductivity
of the soil. Once the creek level has dropped below the groundwater
level, outflow of ground water may occur. Specific geologic areas within
the marsh also may act as drainage conduits for localized portions of the
marsh, including those composed of sand, peat or shingles. Their pre-
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HIGH
SURFACE
DRAINAGE
REPEAT LATERAL
CYCLE SEEPAGE
WATER
TABLE
DRAINAGE
CREEK FLOW
DUE TO
DRAINAGE OF
FW RUNOFF
OR SPRINGS
Figure 5.3-2. Wetland Water movement during Tidal Cycle.
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sence 1n a proposed wastewater discharge site must also be considered
when evaluating detention time and short circuiting potential.
5.3.4 Buffering
Buffering is the term used to describe a wetland's ability to limit
the effect of major hydrologlcal events, such as high seas, rainfall and
freshwater flooding. In this respect, saltwater wetlands aid 1n the
reduction of freshwater peak flows from rivers by temporary storage, thus
easing the Impact on estuarlne salinity by spreading out the Influx of
freshwater temporally. Additionally, saltwater wetlands act as a buffer
between the seas and shoreline to prevent erosion. However, In
catastrophic flooding caused by winds, high tides and storm surge, buf-
fering capacity may be relatively small (Greeson et al., 1978).
5.3.5 Storage
Storage of water within a saltwater wetland can be divided Into two
categories, ground and surface. Groundwater offers the largest storage
volume within the wetlands. However, due to frequent Inundation 1n most
areas of consideration, available excess storage 1s usually limited.
During periods of excess dryness, such as may occur 1n Gulf coastal areas
in the winter, groundwater storage may provide the major source of water
for marsh vegetation. Surface storage 1s generally very temporary.
Storage of precipitation, river or tidal Inflow can only be accomplished
in pools created by Irregularities in the surface or In the channels and
creeks running through the marsh.
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5.3.6 Hydraulic Loading
Hydraulic loading 1s the physical volume of water that can be
applied to a wetland by natural fluctuations of tide, precipitation and
rivers. This factor Is dependent upon site-specific characteristics.
The type of vegetation found 1n a salt marsh 1s generally determined by
the frequency, duration and depth of flooding. Some plants may survive
under hydraulic loadings greater than that which occurs naturally.
However, specific limits have not been accurately established for vegeta-
tion associated with saltwater marshes, and a change 1n the makeup of
biota may follow a change in hydraulic loading. Characteristics to con-
sider 1n the evaluation of wastewater discharges should include the
effects of increased hydraulic loading on vegetation and animal life and
the Impact of Increased soil saturation periods, Increased runoff and
decreased storage-capacity. Additional discussion of hydraulic loading
is Included 1n Section 6.0 of this report.
5.3.7 Impacts From Wastewater Effluent Application
Saltwater wetlands have evolved naturally to an equilibrium point
based upon the amount of water and nutrients available, frequency and
duration of Inundation and soil moisture characteristics. Alterations to
any of these parameters may cause a change 1n the biological and physical
characteristics of the marsh. Whether these changes would be detrimental
or beneficial would depend upon the specific characteristics of the site
under consideration.
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Some Impacts which may be associated with wastewater discharges to
wetlands Include alteration of vegetation types as a result of continual
saturation of the surface, Increased erosion and detritus removal from
runoff, or possibly decreased erosion due to Increased vegetative growth
as a result of Increased nutrient availability. Seasonal variations 1n
wetness and dryness within the wetland may be altered by the continual
application of wastewater effluent. Additionally, anaerobic conditions
1n marsh soils may be exacerbated by the continual Inundation by a layer
of oxygen-depleted water. Anaerobic conditions may limit the availabi-
lity of soil nutrients for biological use. Additionally, the application
of wastewater may alter the salinity of water on the marsh, 1n marsh
soils, and eventually In the receiving estuary.
5.4 WATER QUALITY
Maintaining water quality 1n wetlands receiving wastewater Involves
many components of the wetland system. Water quality changes occur as a
result of geomorphologlcal, hydrologlcal and biological activities. The
many complex Interrelationships within a saltwater wetland ecosystem make
the evaluation of specific water-quality Impacts a difficult task, since
other components are always Involved. Consequently the following sec-
tions discuss water quality In terms of the relation of surface water to
other components of the saltwater wetland and their dynamic Interactions.
The available data on wetland water quality 1s largely quantitative and
site specific; thus conditions 1n one saltwater wetland do not exactly
match conditions 1n another wetland.
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5.4.1 General Water-Quality Parameters
Many water-quality parameters need to be considered when charac-
terizing a saltwater wetland. Dissolved oxygen (DO), salinity, hydrogen-
Ion concentration (pH), suspended sol Ids (turbidity), organic load
(seston), water color, oxygen-demanding substances (BOD, COD), viruses
and bacteria, and refractory (stable, persistent) chemicals such as metal
oxides and pesticides are all important factors when evaluating the addi-
tion of wastewater effluent to coastal wetlands. Several of these para-
meters are discussed below to help characterize natural salt-marsh and
mangrove habitats. Nutrients and heavy metals are discussed in Section
5.4.2.
5.4.1.1 Salt Marsh Characteristics
Dissolved Oxygen
Salt marshes are characterized by anaerobic (without oxygen) con-
ditions In the sediments, particularly just beneath the surface of the
substrate. Microbial activity at the marsh's surface leads to a rapid
consumption of oxygen. In addition, regular tidal flooding of marshes
can leave water 1n the interstitial sediment spaces, thus decreasing the
rate at which gaseous oxygen can permeate the soil (Teal and Teal, 1969).
However, sediment oxidation can occur through the release of organic oxi-
dants by plant (Spartina) root systems (Valiela et al., unpublished).
Sediments associated with Spartina roots, therefore, are more oxidized
than bare sediments. Additional aeration of sediments could result form
animal activity, such as sorting of the sediments by detritus-feeders
(e.g. the crab Uca) or burrowing of crabs.
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Surface waters flooding coastal-marsh sediments, particularly in
tidal areas, are usually more oxygenated than sediments. Turbulence
caused by changing tides can increase the dissolved oxygen in the marsh.
However, much of the dissolved oxygen added to the marsh surface during
tidal flooding is offset by the high rate of oxygen consumption at the
surface (Teal and Teal, 1969). Superimposed on this tidal cycle of
dissolved oxygen is a diel cycle. Photosynthesis produces oxygen in
vegetated marshes during daylight hours. Studies of the Tinicum Marsh,
near Philadelphia, have shown that the oxygen content of water was
increased by filtering through the marsh (Horwitz, 1978). In the
evening, when photosynthesis subsides and plants consume oxygen, DO
levels in coastal marshes are reduced. Tidal flow from oxygenated
estuaries, however, helps to offset reduced DO levels, and cooler evening
temperatures allow for slightly greater oxygen saturation.
The saturation level of dissolved oxygen is highly dependent on tem-
perature and salinity. Saturation values are low, for example, when tem-
perature and salinity values are high. Dissolved oxygen values also may
vary with water depth, generally decreasing with depth.
The amount of dissolved oxygen in the sediments and surface waters
of coastal marshes is an important factor in determining the potential of
salt marshes to assimilate wastes. The biotic community and microbial
decomposition that occur in the marsh are partially dependent upon the
availability of dissolved oxygen. The fresh water of the effluent
theoretically could hold more dissolved oxygen than could the more saline
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water of the salt marsh. In addition, any turbulence created during
application of the effluent could effect a slight localized increase in
the amount of dissolved oxygen 1n the marsh. However, the addition of
wastewater to saltwater wetlands presumably would Increase the biological
and chemical demands for oxygen, thus further decreasing the dissolved
oxygen available to the marsh community. The effect of the wastewater
upon dissolved oxygen in the marsh, and subsequently upon the marsh flora
and fauna, would be dependent upon the content of the wastewater and the
area of the wetland receiving the effluent.
Salinity
Saline surface waters are characteristic of coastal marshes,
although some Inland marshes also may be somewhat saline. Coastal
marshes of estuarine and marine systems can be described as hyperhaline
(>40 ppt), euhaline (30.0-40 ppt), mixohaline/ brackish (0.5-30 ppt),
polyhaline (18.0-30 ppt), mesohallne (5.0-18 ppt), ollgohaline (0.5-5
ppt) or fresh (<0.5 ppt; Cowardin et al., 1979). Factors such as fre-
quency and degree of tidal Inundation, freshwater input from precipita-
tion or tidal creeks, and drainage related to topography (e.g. pools or
salt pannes left in higher saltmarsh areas) can result in salinity
variations over time and at different locations within a salt marsh. For
example, the salinity range for surface and sediment waters in a Delaware
marsh was greater for bare bank and panne areas. These areas were not
covered by leafy vegetation and thus had greater rates of evaporation,
resulting in higher salinities (Sullivan, 1971). Salinity Influences the
distribution of marsh vegetation, such as Spartina grasses (see Section
5.2.1) and animals (Daiber, 1977) within the marsh.
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The addition of freshwater-diluted sewage into a salt marsh would
reduce the salinity somewhat. Seafood-processing effluent would have a
similar effect, unless the effluent itself included brine and other
saline waters used in seafood processing (see Figure 6.2-2 and Table
6.2-2). Depending upon the degree of salinity change, the effluent could
cause changes in the chemical associations and reactions within the
marsh. For example, the metal cadmium forms chloro-complexes at higher
salinities, thus decreasing the free ion concentration of the metal and
decreasing its subsequent toxicity (Engel et al., 1981). Salinity-
related chemical changes also could affect the floral and faunal struc-
ture of the marsh over time. Freshwater irrigation of short Spartina
al term' flora in a Delaware salt marsh resulted in significantly greater
live leaf production and an extension of the growing season (Hardiskey et
al., 1983). The authors proposed that the freshwater created "a more
positive soil osmotic potential and increased soil water movement",
resulting in a "potentially greater uptake of existing interstitial
nitrogen by the plants." Thus, the fresher water of wastewater effluent
might facilitate the uptake of some nutrients by salt-marsh plants.
Dissolved salts buffer marsh surface waters so that the pH values
are generally in the neutral range. The pH levels in sediments can vary
from acidic to alkaline, depending upon the location within the marsh,
time of day, season, and degree of tidal inundation. Sediment pH values
in the Great Sippewissett Marsh in Massachusetts, for example, varied
between 5 and 6.5 (Giblin et al., 1980).
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In the Canary Creek marsh 1n Delaware, pH measurements were taken at
five different saltmarsh areas (tall Spartina alternlflora, bare bank,
dwarf or short J5. alternlflora. D1st1ch11s splcata. and panne) over a
12-month period (Gallagher, 1971). The pH of surface water 1n the five
areas was generally neutral to slightly alkaline, with an annual range of
7.25-9.15. The annual range for pH of the sediment surface at all five
areas was 6.25-9.00; pH of the sediment surface was neutral to slightly
alkaline 1n all areas except 1n the short j>. alternlflora, where pH was
slightly acidic to neutral. The highest pH values for both surface water
and sediment surface were found In the panne in August. A high pH of
surface water 1n the marsh was associated with high algal activity on the
mud surface (Sullivan, 1971). Sediment pH increased with depth 1n the
tall _S. alternlflora area but usually decreased with depth 1n the panne.
In the Mission Bay marsh in California, the pH of sediment water varied
from 6.8-8.3 (Phleger, 1977). The pH varied depending upon the time of
day and the tidal stage in areas subject to tidal inundation. However,
the monthly mean pH was near neutral. In the four different microhabi-
tats tested within the marsh, the pH of sediment water was shown to
decrease with depth. The relatively high pH (7.2-9.5) of salt marsh
sediments studied in the Netherlands was related to the high carbonate
content of the sediments and availability of Ions through tidal flooding
(Beeftlnk et al., 1977).
The pH levels found 1n a salt marsh play an important role In the
dymanic processes occurring within the marsh. The pH of surface water or
sediments can be an indicator of chemical reactions occurring within a
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salt marsh. For example, microbiological processes can convert organic
sulfur or sulfate into hydrogen sulfide (H2S) in the anaerobic saltmarsh
sediments. If the sediments are aerated, the H2$ can be oxidized to
sulfuric acid (H2$04), which results in an acidic pH at the sediment sur-
face. In the presence of carbonates or of ions brought into the marsh by
tidal action, the HgSCty can be converted to gypsum (CaSO/i), yielding a
more neutral pH (Beeftink et al., 1977). Gooch (1968) discussed the
relationship of pH of saltmarsh water and seasonal cycles of both anaero-
bic microbial sulfide production and availability of dissolved phosphate
in a Delaware marsh. In addition, the more acidic sediment of short
Spartina alterniflora areas results in more phosphate going into solution
and being available for uptake by algae and higher plants (Daiber, 1972).
The pH level of most domestic wastewater is neutral and well buf-
fered, while that of seafood-processing effluent may be slightly alkaline
(see Table 6.2-2). The effects wastewater has on the pH of saltwater
wetlands depend on the volume of wastewater discharged and the buffering
capacity of the wetland. A well-buffered wetland system tends to main-
tain a constant pH.
Turbidity
Turbidity in coastal marshes is caused by biological and physical
factors such as plankton, land runoff, suspended organics and sediment,
pollutants, and humic and tannic acids. Often, however, the primary
source of turbidity is detritus that has been broken down by microorgan-
isms (Gulf South Research Institute, 1977). Tidal flow can reduce tur-
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bldlty by transferring detritus to the estuary, but it also may
contribute to turbidity by Importing turbid or polluted waters and by
causing turbulence that resuspends sediment participates.
Wastewater effluent could add to the turbidity of water 1n the marsh
1f 1t contains an appreciable concentration of suspended solids or
creates turbulence (I.e. resuspends detritus, sediment) during Its Intro-
duction Into the marsh. Increased nutrient levels from wastewater
effluent also could Increase turbidity by Increasing productivity of
plankton populations.
5.4.1.2 Mangrove Community Characteristics
Surface waters 1n mangrove communities can be characterized by sali-
nity values ranging from near fresh to 40 ppt; DO levels between 2 and 4
ppm or near zero 1n stagnant areas or 1n areas of runoff; low total
phosphorus values; moderate nitrogen levels (0.5 to 1.5 mg/1); total
»
organic carbon (TOC) ranging from 4 to 50 ppm or higher; dissolved orga-
nic carbon (DOC) as high as 110 ppm; turbidity within 1 to 15 Jackson
Turbidity Units (JTU); and pH (1n Florida swamps) between 6.5 and 8.0
with alkalinity between 100 to 300 mg/1 (Odum et al., 1982). These
values are approximate and can vary with natural and human perturbations.
Although the specific effects of wastewater addition to mangrove
communities are not known, changes 1n water quality might be similar to
those discussed for salt marshes (Sections 5.4.1.1 and 5.4.2) and would
be dependent upon the natural characteristics of the particular mangrove
community under consideration.
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5.4.2 Nutrient Removal and Metal Uptake
Application of secondary-treated wastewater to saltwater wetlands Is
a process that is gaining attention as a potentially economical, energy
efficient method of nutrient removal compared to the cost of advanced
wastewater treatment plants (Gosselink et al., 1974). However, economics
is only one consideration when evaluating saltwater wetlands for
wastewater management. The mobility, absorption/adsorption and translo-
cation of heavy metals and pesticides also must be considered since
marsh-estuary systems recycle nutrients through many food chains.
Few studies have been conducted to determine the effects of nutrient
additions to saltwater wetlands through the application of wastewater
effluent. Studies conducted by Teal and Vallela (1973) and others have
demonstrated that salt marshes are capable of removing nutrients such as
nitrogen from applied secondary-sewage sludge. Although the present
assessment is not concerned with sludge disposal and sludge cannot be
discharged to a wetland system because of their designation as "waters of
the United States", the referenced examples of sewage-sludge applications
are helpful in exploring the potential for saltwater wetlands to utilize
sewage nutrients. At the same time, one must keep in mind that the
physio-chemical and microbial composition of secondary-sewage sludge
differs from that of wastewater effluent, so that the availability of
nutrients in wastewater may differ from that 1n sludge.
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5.4.2.1 Nutrients
Nutrients basic to living organisms are nitrogen, phosphorus, sulfur
and carbon (USEPA, 1983). While Section 5.1.3.1 describes these
nutrients in soils, this Section Is relevant to the discharge of effluent
into saltwater wetlands and water quality. The discussion focuses on two
of the more essential nutrients, nitrogen and phosphorus. Of these two
essential nutrients, nitrogen 1s usually the limiting nutrient in salt
marshes (Valiela et al., 1973). The fine-grained organic muds of salt
marshes usually contain sufficient amounts of other nutrients supplied by
the tides and trapped in the mud (Teal and Valiela, 1973).
Nitrogen
Nitrogen in wetlands is present as inorganic (NH^, N02» NO?),
gaseous (NH3, N£ and N oxides) and numerous organic forms (Nichols,
1983). Nitrogen is used or removed from marshes through 1) tidal
nutrient export ("outwelllng"; Odum, 1971), 2) plant uptake primarily
from sediments, 3) bacterial and algal fixation and 4) anaerobic bac-
terial denitrlfication (Teal and Valiela, 1973; Nichols, 1983). The con-
sequences of these processes, respectively, are 1) estuarine nourishment
with nutrients and detritus, 2) Increased plant production, 3) formation
of chemically-bound nitrogen (nutrient form) from nitrogen gas and 4)
production of gaseous nitrogen from nitrate, which is utilized as an oxy-
gen substitute under anaerobic conditions. Sources of nitrogen are the
atmosphere through nitrogen fixation and estuaries and/or rivers that
supply nitrogen through tidal or river currents. Nitrogen fixation
ceases in the presence of adequate nitrogen (Teal and Valiela, 1973) that
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can be supplied by tides, rivers or other non-atmospheric sources. Marsh
vegetation can, therefore, apparently survive through periods of low
nitrogen availability through nitrogen fixation, but forego the nitrogen
fixation process and utilize nitrogen when available from natural exter-
nal sources.
Experiments involving the artifical fertilization of salt marshes
with commercial secondary-sewage sludge have been performed in
Massachusetts. Sludge, as opposed to effluent, was chosen to facilitate
application and includes toxins such as PCB's, pesticides, heavy metals
and hydrocarbons trapped in the sludge (Teal and Vallela, 1973).
According to Vallela et al. (1973), the retention of applied sewage
sludge nutrients in the salt marshes can be substantial. Teal and
Valiela (1973) applied up to 70 gN/nr/year, of which approximately 15 g N
were washed away by high tides soon after fertilizer application. (Using
the effluent total nitrogen concentration of 25 mg/1 from Table 6.1-2, 70
g N is contained in 2800 1 of wastewater effluent). Nutrient losses were
related to tidal exposure and amount of sludge application, with a
greater application resulting 1n a greater percentage loss.
In addition to being removed from the salt marsh, nitrogen 1s also
conserved and recycled within the saltwater-wetland ecosystem. Dissolved
nitrogen forms (particularly ammonium and nitrates) are taken up by
plants and bacteria and stored as blomass for varying periods of time.
In general, application of nitrogenous nutrients can result in nitrogen
uptake and increased plant blomass in nitrogen-limited systems but essen-
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tially no growth change for non-nltrogen-Hmited systems. In saltmarsh
areas where the supply of nitrogen 1s limited (e.g. higher marsh areas
containing the short form of S. alterniflora), nitrogen could be removed
from wastewater through incorporation Into production of plant biomass.
However, in areas where the availability of nitrogen 1s not a limiting
factor in plant production (e.g. low marsh or creek bank areas containing
tall S^ alterniflora), or if the application of wastewater nitrogen
exceeds the capacity of the plants to utilize it 1n biomass production,
more wastewater nitrogen could potentially be washed out of the marsh and
enter an estuary. Plant species vary in the amount of nitrogen they can
assimilate, and nitrogen loading limits have been observed in some
plants. For example, the peak above-ground biomass of Spartlna alter-
niflora measured from the Great Sippewissett salt marsh leveled off after
a sludge-fertilizer application of approximately 50gN/m2/year, while
Distichlls splcata biomass values continued to rise with applications of
over 200gN/m2/year (Valiela et al., unpublished). (Again using Table
6.1-2, 50 gN would be contained in 2000 1 of wastewater, 200 g N in 8000
1 of wastewater.) Annual peak above-ground biomass of £. alterniflora
increased during the first four years of sludge fertilizer application
but then decreased. Over a period of several years, D_. spicata replaced
JS. alterniflora in high marsh areas of the test plot.
In addition to increasing plant productivity, the use of effluent
fertilization may also extend the growing season. Hardisky et al. (1983)
reports that the short form of £. alterniflora from a Delaware salt marsh
irrigated with freshwater and primary-treated sewage effluent had its
growing season extended by two months, with growth ceasing 1n October.
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Wetland vegetation can absorb large amounts of nitrogen and
phosphorus during the growing season, yet much of the stored nutrients
can be released to the water when the plants die. When nitrogen 1s
released by plants during decomposition of dead plant matter, 1t can
either be recycled again, exported, or lost to sediment. Algae and bac-
teria also may temporarily store nitrogen unless 1t 1s trapped 1n sedi-
ments. Ammonia or nitrate-nitrogen may be taken up by plant roots for
nutrition or may remain 1n organic matter until 1t Is degraded or flushed
out by tidal action. Figure 5.1-5, previously shown, depicts the nitro-
gen cycle.
Wastewater nitrogen applied to a wetland also can be removed from
the wastewater by anaerobic bacterial denltrlflcatlon in the soil.
Denitrification requires a source of available organic carbon, which
would be abundant 1n a salt marsh. However, the efficiency of nitrogen
removal through denitrification decreases at higher loading rates
(Nichols, 1983).
Because nitrogen is often the limiting nutrient for saltmarsh plants
and nitrogen fixation is cut off when external nitrogen supplies are suf-
ficient, salt marshes provide an environment that 1s potentially suitable
for nitrogen enrichment by sewage and seafood-processing effluents. Such
enrichment would enhance plant productivity and detrltal formation as
well as remove nitrogen from wastewater effluent. However, the
wastewater nitrogen bound in plant biomass could potentially be
transported from the saltwater wetland Into an estuary, depending upon
the rate of decomposition and frequency of tidal inundation.
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Phosphorus
The phosphorus cycle Is somewhat simpler than the nitrogen cycle.
One significant difference between the two is that phosphorus cannot
enter or leave a saltwater wetland In a gaseous form. The natural reser-
voir for phosphorus 1s rocks or other geological deposits. Inorganic or
organic phosphorus normally enters saltwater wetlands from surface
waters, groundwater, rain, or runoff depending on site-specific con-
ditions.
Phosphorus 1s converted from Its organic form to Inorganic
phosphorus 1n the sediments (Section 5.1.3.1) or 1n the wetland surface
waters by hydrolysis. Figure 5.1-6, previously shown, presents the dif-
ferent pathways that exist for phosphorus. The pattern of phosphorus
assimilation and release 1s dependent upon hydrologlc conditions, vegeta-
tion, and sediment types of each wetland.
Wastewater phosphorus 1s readily retained 1n soils by adsorption and
precipitation reactions with aluminum, Iron, calcium and clay minerals
(Nichols, 1983; see Section 5.1.3.1). Continued Introduction of
wastewater phosphorus to wetlands decreases the ability of wetland soils
to retain phosphorus as the soils become saturated (Nichols, 1983).
However, some phosphorus that Is adsorbed from the water at high con-
centrations can be released to the water when phosphorus levels decrease.
For example, when inorganic phosphate was applied to the surface of the
Rhode River marsh 1n Massachusetts at a rate of 4.3 kg/ha/day (1 hectare
- 2.47 acres) the binding capacity of the sediment was exceeded in 45
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days (Bender, 1974). Test plots In the Great S1ppew1ssett marsh fer-
tilized with 600 kg/ha/year of a phosphate fertilizer showed a rapid
buildup of dissolved phosphate 1n the sediment water to approximately 11
mg/1 of phosphate phosphorus, with no Indication of depletion over the
winter when fertilizer application was halted. The system was overloaded
and loading rates were reduced the following year, resulting 1n dissolved
phosphate concentrations being decreased (Vallela, 1973). The removal of
wastewater nitrogen and phosphorus by wetlands 1s most efficient at low
loading rates. Citing studies of freshwater wetlands, Nichols (1983)
reports that 1 hectare (2.47 acres) of wetland on the average 1s required
to remove 50 percent of the nitrogen and phosphorus from the wastewater
produced by 60 people. Higher removal rates require larger wetlands.
The mechanisms for nutrient removal from wastewater 1n a saltwater
wetland differ somewhat from those 1n a freshwater wetland, yet effi-
ciency of removal would still be affected by loading rate.
Phosphorus 1s utilized by saltmarsh vegetation but 1t Is apparently
not a limiting factor 1n production of saltmarsh plants (Halnes, 1979).
Thus, In contrast with nitrogen, removal of wastewater phosphorus through
plant production would not necessarily be enhanced by adding the effluent
to areas containing a particular type of saltmarsh vegetation.
Wastewater phosphorus utilized 1n plant production could eventually
reenter water 1n the saltmarsh during decomposition of the vegetation.
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5.4.2.2 Heavy Metals
Heavy metals and other toxins (pesticides, PCB's and hydrocarbons)
that may be present in wastewater effluent must also be considered 1f
saltwater wetlands are to be used as wastewater discharge systems. Toxic
trace metals Include copper, mercury, silver, chromium, cadmium, zinc and
nickel (Engel et al., 1981), plus arsenic and lead. Conversely, some
trace metals are mlcronutrlents. These are Iron, zinc, copper, manga-
nese, cobalt and molybdenum (Engel et al., 1981). Copper and zinc are
either trace metals or mlcronutrlents depending on their concentration.
Heavy metals may enter a wetland ecosystem through several pathways
of transport and translocatlon Including movement of surface or ground-
waters Into the sediments, atmospheric fallout, and uptake by plants or
animals. The form the metal takes 1n water Is dependent on the Indivi-
dual metal, Its concentration, and the chemical components and physical
characteristics of the water, Including Its pH, salinity, presence of
dissolved organlcs and conditions of oxidation or reduction (Engel et
al., 1981). The chemical potential of a metal Is an Important variable
1n determining trace metal Interactions with the biota present.
Examples of chemical forms of trace metals In natural waters Include
free tons, metals adsorbed on or Incorporated Into particulate matter,
organic complexes and Inorganic complexes (Engel et al., 1981). An
example of an Inorganic complex 1s a metal-sulflde complex, such as Iron
sulflde (FeS2), which 1s Insoluble and will precipitate. Metal chloride
complexes, such as zinc chloride (ZnCl2) and cadmium chloride (CdCl2),
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are soluble and present in saltwater (G1bl1n et al., 1980). In general,
heavy-metal and chlorinated-hydrocarbon uptake by living organisms 1s
increased by solubillzing conditions and Is decreased by conditions asso-
ciated with partlculate phases (National Wetlands Technical Council,
1978). For example, the iron in water entering a salt marsh reacts with
sulfides in the anaerobic sediment, thus forming Insoluble Iron sulflde
(Fe$2). Diffusion of excess oxygen through the roots of _S. alterniflora
can oxidize iron sulflde and form insoluble iron oxide (rust) plus
soluble ferrous sulfate, a form of iron that can be utilized by the plant
(Teal and Teal, 1969).
Trace metal studies of copper, cadmium and silver demonstrate the
complexity of aquatic chemistry and suggest that broad generalizations
about metal chemistries and biological effects cannot be made (Engel et
al., 1981). The free 1on concentration of copper and cadmium, for
example, appears to determine toxiclty and bloaccumulation 1n marine
organisms. As salinity increases, copper and cadmium ions form chloro-
complexes, thus limiting their potential uptake by organisms. Silver
also forms chloro-complexes as salinity increases; however, Us accumula-
tion by organisms at lower salinities is apparently related to both the
free silver Ion concentration and chloro-complexes. Thus the speciatlon
of trace metals in water determines their toxicity and bloaccumulation In
organisms exposed to water containing the metals.
The conclusions made by Engel et al. (1981) are supported by studies
of the effects of metals added to salt marshes. For example, test plots
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1n the Great Sippewissett Marsh in Massachusetts were treated with fer-
tilizer containing secondary-sewage sludge (Including metals) over a
seven-year period. Changes were exhibited 1n metal content for marsh
sediments, grasses and animals (G1bl1n et al., 1980). Iron and lead were
held 1n sediments in forms unavailable to marsh plants and animals (e.g.
Iron sulflde, FeS2). Copper was similarly retained in sediment but was
available to the biota. Chromium, cadmium and zinc were found to be
highly mobile In treated plots and were utilized by the marsh plants and
animals. In general, marsh sediments showed a retention of 20 to 35 per-
cent for cadmium, 20 to 50 percent for chromium, 60 to 100 percent for
copper, 55 to 100 percent for lead, 80 to 100 percent for Iron, 55 to 60
percent for manganese and 20 to 45 percent for zinc added by the fer-
tilizer. The high marsh area retained a considerably greater percentage
of metals (except manganese) than the low marsh area, presumably because
the low marsh was flooded by tides more often. Nixon (1982) also
reported that lead, copper and iron were very tightly held by New England
high salt marshes, while manganese, zinc and chromium showed only about
50 percent retention and cadmium somewhat less.
Removal of metals from wastewater added to a saltmarsh is thus a
complex process. Although metals can be removed from the water and
retained 1n the sediments, they can also be Incorporated into plant and
animal tissues. Animals feeding upon plants or detritus In>the marsh
accumulate these metals in their tissue and, In turn, pass these toxins
up the food chain (bioaccumulation). The level of bioaccumulation varies
with species and with the type of metal. (Section 5.5.6 discusses these
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impacts to wildlife.) Metals accumulated in the tissues of marsh biota
can potentially be reintroduced to the marsh water during decomposition
of organic matter.
5.4.2.3 Pathogens
Secondary treatment of wastewater removes or destroys 90-98 percent
of the bacteria present, while subsequent chlorination of this treated
wastewater yields a 98-99 percent removal of bacteria (Metcalf and Eddy,
Inc., 1979). However, chlorine is not as effective in inactivating
enteroviruses (Weber, 1972). Most current disinfection techniques do not
completely inactivate hepatitis and polio viruses.
Pathogens settled in sediments may be resuspended by physical
disturbances such as dredging (Taylor, 1973). El lender et al. (1980)
reported that viruses can remain infectious in sediments and be returned
to the water column through physical or chemical action. Fecal bacteria
counts, however, are much reduced as compared to primary-sewage effluent,
because of chlorination. If pathogenic bacteria or viruses are
introduced to a saltmarsh through wastewater effluent and are
subsequently carried out of the marsh through tidal action or stormwater
drainage, they could potentially reach shellfish beds. Consumption of
raw shellfish contaminated by sewage can result in the transmission of
infectious hepatitis to humans (Kilgore and Li, 1980).
While chlorination of treated wastewater is of great importance in
decreasing bacterial populations, chlorine Itself could be detrimental to
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the natural mlcroblal population of a saltwater wetland. Dechlorlnation
of treated wastewater prior to its addition to a saltmarsh would thus be
highly desirable.
5.4.3 Assessment
Water quality of a saltwater wetland is dependent upon the complex
physical and chemical reactions occurring within the wetland. The degree
of change in water quality within a saltwater wetland receiving a
wastewater addition would depend upon the physical and chemical charac-
teristics of both the wastewater and the wetland, the fauna and flora
associated with the wetland, and the location, method, volume, timing and
frequency of wastewater application.
The path and rate of movement of wastewater through a saltwater
wetland would affect changes in water quality within the wetland.
Application of wastewater 1n high marsh, rather than low marsh, areas
would allow greater interaction of wastewater and the wetland, thus
allowing more wastewater components to be retained within the wetland
rather than being carried out relatively unchanged into an estuary.
The fate of components of wastewater, such as nutrients and metals,
would depend not only upon their concentration in the water but also upon
their chemical form or spedatlon and conditions in the wetland at the
site and time of application. In addition, a chemical component would
not necessarily remain in one compartment of the wetland. Changes in
physical or chemical conditions could cause a nutrient, for example, to
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be in solution in wetland water, bound in sediments, or utilized 1n plant
or animal production.
Many physical and chemical reactions which occur within a saltwater
wetland have limitations. The limitations of nitrogen utilization by
Spartina and the adsorption of phosphorus by clay sediment particles have
already been discussed. Thus, once the dynamic processes related to
water quality have been defined, it is important to determine the rates
of the reactions and their limiting factors.
Interactions of water (both saline and fresh) with air, soil and
biota cause changes in water quality over time. However, these changes
can be cyclic, occuring on a diel, twice-monthly (related to tides),
monthly (lunar), seasonal or annual basis. The wastewater-effluent and
sludge-fertilizer studies cited earlier in this section were based upon
weekly or twice-monthly applications. In determining loading limits for
components of wastewater added to a saltwater wetland, one must consider
not only the volume of the addition but also the frequency of applica-
tion. A wetland might be more capable of handling a chemical component
applied at low concentrations over longer periods of time rather than the
same total concentration added during fewer applications. On the other
hand, a periodic, rather than constant, application would mimic the
natural tidal cycle of Inundation within the wetland. Many saltmarsh
plants and animals have adapted to these tidal cycles; for example,
J>. alternlflora can survive temporary, but not constant, flooding of the
marsh (Teal and Teal, 1969). Seasonal changes within a saltwater wetland
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can affect Its response to wastewater additions. For example, short
JS. alternlflora can remove Inorganic nitrogen from wastewater only during
Its growing season. During the winter months, wastewater nitrogen could
be removed through algal production or bacterial denltrification, but the
rate of removal might differ. In addition, possible seasonal changes 1n
the water quality and/or volume of wastewater Itself must be taken Into
account.
Application of wastewater to a saltwater wetland can result 1n both
Immediate and delayed changes In water quality. For example, phosphorus
1n wastewater 1s rapidly adsorbed onto clay particles In the sediment and
later resuspended during times of low phosphorus concentration of wetland
water. Although concentrations of toxic heavy metals or pathogens might
be very low In secondary treated wastewater, they could accumulate 1n
wetland sediments or 1n the biota, with the potential for later resuspen-
sion 1n water.
The addition of nutrient-rich wastewater might cause Increased pri-
mary productivity within a wetland. However, Increased productivity
eventually leads to an Increase In dead vegetation. Depending upon the
decomposition rate and degree of flushing 1n that area of the wetland,
nutrients released during decomposition could remain in the wetland sedi-
ment or could reenter the wetland water and possibly be carried out to an
estuary. If the nutrients remain In the wetland area, the ability of the
wetland flora to use the nutrients in subsequent wastewater additions
might be decreased. Thus, if wastewater additions bring about changes in
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the structure of the wetland (Including the floral community) over time,
then changes 1n water quality during subsequent wastewater additions
might differ from those which occurred during the Initial wastewater
additions.
Three other factors might affect water quality within a saltwater
wetland. Wetlands located near developed areas might already be under
stress from pollution and slltatlon. Secondly, the wastewater applica-
tion system would need provisions for handling of wastewater under unu-
sual conditions, such as treatment-system breakdown (Including
chlorlnatlon failure) or extreme weather conditions. Otherwise high con-
centrations of pathogens or toxic chemicals could enter the wetland and
possibly be carried out to an estuary. One last aspect to consider Is
the potential Impact on a wetland which has adjusted to regular
wastewater application 1f wastewater additions are subsequently discon-
tinued.
In summary, the basic water quality changes 1n a saltwater wetland
receiving secondary-treated wastewater or seafood-processing effluent
would probably be as follows:
1. Dissolved oxygen and salinity would decrease.
2. Turbidity would Increase.
3. Potential changes 1n the pH of surface water might be counter-
acted by buffering within the wetland.
4. Nutrients could potentially be removed from wastewater through
utilization 1n plant production or binding In sediments;
however, nutrients could reenter the water during decomposition
of dead vegetation or resuspenslon from sediments.
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5. Heavy metals could be bound 1n sediments or incorporated 1n
plant production; however, the metals might later be resuspended
in the water or they could pass through food chains.
6. Pathogenic viruses or bacteria which settle 1n sediments might
remain viable and might also later be resuspended in water.
Further information 1s needed on the natural physical and chemical
processes occurring within the different types of saltwater wetlands 1n
the Southeastern Region. In addition, the content of particular
effluents should be Identified. More pilot studies would be needed to
determine the effects of secondary-treated wastewater or seafood-
processing effluents on various types of wetlands and different areas
within each wetland. Since environmental conditions are not exactly
alike for all saltwater wetlands, both baseline and operational environ-
mental monitoring would be needed for each wetland under consideration
for wastewater application.
5.5 WILDLIFE
The estuarlne zone, including the salt marsh, forms a vast ecosystem
that provides food, cover and nesting area for an abundance of wildlife
(Sandifer, 1980; Gusey, 1981; O'Neill and Mettee, 1982). The wildlife
species associated with coastal salt marshes are supported by a highly-
productive habitat that is the result of three separate, but Interdepen-
dent, units of primary production. These units are marshes and their
resultant detritus, benthlc organisms, and plankton (Schelske and Odum,
1962; Sandifer et al., 1980; Gusey, 1981).
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The flow of energy through the marsh community starts with the fixa-
tion of sunlight by plants. This primary production 1s the basic form of
energy storage In the ecosystem. The energy stored by plants 1s passed
along through the ecosystem 1n a series of steps known as a food chain.
At each step in the food chain, a considerable portion of the potential
energy is used for maintenance or lost as heat. As a result, organisms
at each trophic (feeding) level pass on less energy than they receive.
Detritus from decomposing salt marsh plants forms the primary basis
of the food chain in south Atlantic and Gulf coast marshes (Shelske and
Odum, 1962; Teal, 1962). Benthlc and planktonlc algae also contribute to
the basis of marsh food chains and Initiate a massive conversion of
energy (Gusey, 1981). Figure 5.5-1 depicts the flow of energy 1n a
representative estuarine ecosystem. This energy, 1n the form of mineral
and organic nutrients, is distributed to all niches within an estuarine
habitat by tidal and wind action, circulation and marsh flushing.
Shallow water and reduced tidal and wave action contribute to the reten-
tion of partlculate matter. These conditions provide suitable habitat
for a variety of organisms.
Bottom-feeding, filter-feeding and burrowing animals directly uti-
lize detritus. Conspicuous algae-detritus feeders are fiddler crabs (Uca
and Sesarma spp.), horse mussels (Modiolus demlssus) and the saltmarsh
periwinkle (Littorina irrorata), In addition to a variety of annelid
worms, oligochaetes and Insect larvae (Odum, 1974). Burrowing animals
also feed on smaller animals, bacteria and minute plants. Intertldal
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Figure 5.5-1.
The estuarine ecosystem of coastal Alabama and representative
energy symbols. (O'Neil and Metke, 1982)
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oyster clusters provide mlcrohabltats and food for other benthlc species
including mud crabs, snapping shrimp, juvenile blue crabs, amphipods,
isopods, polychaetes and small fishes such as gobies and blennles. Most
of these lower levels of the food web exchange and recycle nutrients and
serve as food for larger forms of life such as fishes, birds, reptiles
and mammals.
5.5.1 Fish and Shellfish
One of the most frequently reported functions of an estuary is its
role as a nursery area for many marine organisms (e.g., Atlantic croaker,
Atlantic menhaden, seatrout or drum, blue crab, shrimp, etc.). Many spe-
cies of fish that live or spawn at sea as adults utilize estuaries, tidal
marshes, seagrass beds and mangrove swamps as postlarval forms and as
juveniles. The species of fish and shellfish responsible for more than
85 percent (by weight) of the commercial fisheries landings of the
southeastern Atlantic states (Burrell, 1975) and 98 percent of the
fisheries in the northern Gulf of Mexico (Gunter, 1961) are estuaMne or
estuarine-dependent at some life stage. One group of migrant Atlantic
fishes (croaker, spot) spends their summers in the estuaries and winters
offshore in deep waters. Others, such as flounder, prefer deep waters in
the summer and winter in the estuaries. Anadromous species such as
salmon, shad, alewife and striped bass pass through estuaries and journey
up rivers for spawning. Catadromous species, such as the eel, live 1n
fresh and brackish waters but spawn 1n the sea and the young return to
the estuaries and to fresh waters (Waiford et al., 1972). Estuarine-
dependent species comprise a majority of the recreationally and commer-
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dally Important fisheries of the Gulf and south Atlantic (Beccasio et
al. 1980, 1982).
The most abundant fish and those with the highest annual biomass in
intertidal estuarine wetlands are those that feed on decayed plant and
animal tissue (detritivores) or on plants (primary consumers). Since
feeding behavior often changes as these fish grow, they are not limited
to one trophic level (Sandifer et al., 1980). For the many species that
spawn in estuaries or use them as nursery grounds, an abundant plankton
population is necessary to provide food for larval and postlarval fish
and other forms (Sandifer et al., 1980). Common food relationships are
Illustrated in Figure 5.5-2. Plankton biomass and populations are
usually greater in estuaries than 1n other aquatic habitats (Sandifer et
al., 1980). The proximity of estuarine waters to marsh land Increases
the environmental variables by exposing phytoplankton populations to
urban, Industrial and agricultural discharges, as well as to the normal
constituents of marsh drainage.
5.5.2 Birds
The most conspicuous form of wildlife 1n a salt marsh is the bird
population. Salt marsh vegetation serves as a base for feeding, resting,
reproduction and roosting activities for many breeding and non-breeding
birds. The large avian population consists of shorebirds, wading birds,
waterfowl, raptors, sea birds, songbirds and others. Feeding habitats
provided by marshlands vary with tides, seasons, plant species and vege-
tation height and abundance. The nesting activities of many marsh birds,
5-77
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MUMMICHOG
KILLIFISH
FORAGE
FISHES
ANCHOVEY
MOSQUITOFISH
BASIC NUTRIENTS
AIR, WATER, SUNLJOHT,
ORGANIC MATTER,
MINERALS
INVERTEBRATES
PLANKTON,
ALGAE
Figure 5.5-2. Common Food Relationships,
5-78
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for example, the marsh wren, often occur 1n conjunction with feeding
activities (Sandifer et al., 1980). Other marsh birds (herons, for
example) nest in colonies away from feeding territories. Salt marshes
are also used for surface-roosting species such as the rails, while red-
winged blackbirds, swallows and wrens are plant-roosting species.
Ecologically, the dominant bird species can be grouped according to
their different trophic levels such as birds of prey, fish eaters, sca-
vengers, insect feeders, aquatic plant eaters, those that feed on
benthos, and omnivores (feed on plants and animals) as illustrated in
Figure 5.5-3. Several species of hawks and owls, among other birds of
prey, make use of salt marshes as hunting areas. These birds of prey
feed on other birds such as clapper rails and, to a greater extent, small
mammals including marsh rabbits and rodents. Eagles and ospreys are
heavily dependent on the fish populations of the salt marsh.
Approximately 70 percent of bald eagles nest in marsh or estuarine habi-
tats (Sandifer et al., 1980). Herons and egrets, ibises, spoonbills,
terns and other species found in Atlantic and Gulf coast salt marshes are
predators of fish, shrimp and fiddler crabs.
There is considerable overlap in birds using estuarine and marine
habitats. For example, various shorebirds will use wracks of dead smooth
cordgrass as nesting sites. During long migration seasons, many species
of shorebirds such as plovers and various sandpipers, the long-billed
yellowlegs, oyster catchers and dowitchers will occupy estuarine marshes
(Sandifer et al., 1980). These species consume mostly smaller crusta-
5-79
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RAPTORS
(Birds of prey)
Peregrine falcon
Merlin
Sharp-aklnned hawk
SCAVENGERS
(Feed on refuse, carrion)
Herring gull
Laughing gull
Fleh crow
IN8ECTIVORES
(Feed on Insects)
Barn swallow
American keatral
Long-billed marah wren
AQUATIC HERBIVORES
OMNIVORES
(Feed on plants and animals)
Boat-tailed greekle
Seaside sparrow
Red-winged blackbird
PISCIVORERS
(Feed on fish)
Great blue heron
Foresters' tern
Black skimmer
\
MACROBENTH1VORES
(Feed on macroscopic benthic organisms)
Whit* Ibis
Clapper rail
WMiet
MICROBENTHIVORE8
(Feed on microscopic benthic organisms)
Spotted aandplper
Dunlin
Figure 5.5-3,
Generalized trophic relationships of representative
birds of estuarine emergent wetlands. (Sandifer et
al., 1980)
5-80
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ceans, mollusks and annelids. Fish-eating species such as pelicans and
cormorants also use the estuarine habitats intensively.
Scavengers, such as gulls and fish crows, utilize estuarine shores
and waters during portions o'f the year. Major nesting groups of gulls
and terns are found along both the Atlantic and Gulf coasts, feeding
offshore and in estuaries and breeding on the beaches and islands.
Birds very often represent end-points in the consumer food chains of
salt marshes (Gusey, 1981). This is often the case with insectivores.
Insects serve as an important food source in the wetland community. They
depend on detritus, algae and saltmarsh vegetation and, in turn, are
preyed upon by various species of birds including marsh wrens, swallows,
kestrels, warblers, blackbirds and sparrows. Species from all major
Insect orders have been recorded from salt marshes. Approximately 75
percent of those salt marsh species recorded consist of Diptera (flies,
mosquitos and midges), Coleoptera (beetles) and Hemiptera (true bugs).
The most important birds of sporting interest in estuaries are the
waterfowl such as ducks and geese. Nearly every American waterfowl spe-
cies inhabits estuarine areas at some point in its life (Sandifer et al.,
1980). For some, such as brant, the estuaries provide all their needs.
For others, salt marshes provide resting grounds, food and refuge during
migration and wintering (redhead, gadwall, teals, black duck, canvasback,
wigeon, etc.). Submerged aquatic vegetation provides most of the food
for these species. The only reported waterfowl whose entire nesting
5-81
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range Hes along the south Atlantic and Gulf coast 1s the Florida duck
(Gusey, 1981).
5.5.3 Reptiles and Amphibians
Most amphibians and reptiles are associated with freshwater, marine
or terrestrial habitats, although some are Infrequently encountered 1n
saltwater wetlands (Beccaslo et al., 1980, 1982; Sandlfer et al., 1980;
O'Nell and Mettee, 1982). Most records are of Individuals reported from
particular locations but, because of the similarity of saltwater-wetland
habitats along the south Atlantic coast and the Gulf coast, the species
mentioned below would be expected to occasionally visit or utilize other
saltwater-wetland habitats given similar conditions.
The amphibian population 1s comparatively small In a salt marsh.
Some of the more commonly reported species Include: southern toads,
observed in irregularly flooded areas (for example Shackelford Banks,
NC), and eastern narrowmouth toads reported 1n glasswort flats 1n Florida
(Engels, 1952; and Nell, 1958, respectively). Other frogs associated
with saltmarsh vegetation Include grass frogs, green tree frogs, chorus
frogs, squirrel tree frogs and southern leopard frogs.
Snakes have occasionally been sighted 1n saltwater wetlands and
include the banded water snake, eastern mud snake, cottonmouth, yellow
rat snake, rough green snake, saltmarsh water snake and brown water snake
(Sandlfer et al., 1980; O'Nell and Metter, 1982). Eastern garter snakes
and Island glass lizards were also found 1n association with fiddler crab
burrows.
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Estuarine waters are also frequented by marine species of turtles.
The Atlantic loggerhead, Atlantic leather-back and Atlantic green turtles,
for example, are reported to ascend tidal creeks to the freshwater zone
and above (O'Neil and Mettee, 1982). Diamondback terrapin occur in
coastal rivers, creeks and estuaries of the coastal salt marsh, par-
ticularly over shell bottoms and near oyster bars. Preferred food items
include snails, fiddler crabs, annelid worms and smooth cord grass
(Sandifer et al., 1980). Other species associated with coastal salt
marshes include the striped mud turtle and the eastern mud turtle. The
snapping turtle and chicken turtle are commonly hunted for food in the
Alabama coastal area (O'Neil and Mettee, 1982).
Alligators will enter brackish water and coastal marshes (Parker and
Dixon, 1980). Their diet varies and includes reptiles, mammals, amphi-
bians, birds and fishes. The American alligator occurs from North
Carolina southward around the coastline to Corpus Chrlsti, Texas, encom-
passing the study region. The American crocodile occurs in salt or
brackish waters of extreme southern Florida.
5.5.4 Mammals
Many mammals thrive in estuarine areas including small rodents, fur-
bearers and large animals such as deer. Aquatic species such as manatees
and porpoise also live within the study region.
The marsh rabbit constitutes an important link in the food chain to
birds of prey. It has been reported that the marsh hawk 1n salt marshes
5-83
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of South Carolina and Georgia depends primarily on marsh rabbits during
winter (Sandifer et al., 1980). Other objects of prey include the marsh
rice rat and the cotton rat (Sharp, 1962; O'Neil and Metter, 1982). The
marsh rice rat is among the most highly aquatic of the coastal rodents
and is an important predator and prey, feeding on fiddler crabs, insects
and wren's eggs. The coastal race of the swamp rabbit is restricted to a
narrow belt along the Gulf coast of Alabama (O'Neil and Mettee, 1982).
Furbearers are relatively abundant in salt marshes and include the
river otter, muskrat, raccoon, mink and nutrea, which are a basis for
valuable fur industries in some states. Weasels, opossum, foxes and bob-
cats are also occasionally taken in the marshes by trappers (Sandifer et
al., 1980; Gusey, 1981). The diet of furbearers is comprised of fish and
crustaceans, and sometimes insects, birds, rodents, oysters and clams.
The young of these mammals may be taken by birds of prey; as adults,
natural mortality may occasionally be caused by alligators or bobcats.
Larger mammals include white-tailed deer, which often graze in the
high marsh, feeding on saltmeadow cordgrass or glasswort. The manatee
spends its entire life in water. In winter the manatee lives in the
southern half of the Florida peninsula and, in summer, it moves north and
west along the Atlantic and Gulf coasts to North Carolina and extreme
western Florida (Parker and Dixon, 1980). Individuals have also been
observed on the northern Gulf coast from Pensacola to New Orleans (O'Nell
and Mettee, 1982).
5-84
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5.5.5 Threatened and Endangered Wildlife Species
Saltwater wetlands harbor a wide diversity of fish and wildlife,
many of which are dependent on this habitat type for survival. Adequate
tracts of these wetland areas are therefore needed if many species are to
remain in existence. The density and diversity of species present in
saltwater wetlands depends on the needs of the species, the ecological
status of the wetland, the population status of the species where the
wetland is located, climate and other factors. The causes of population
increases or declines for coastal species are highly variable; however,
the key element in the decline of many species is the growth of the human
population into coastal areas. The spread of environmental contaminants
along with alteration of land-use patterns associated with development
may contribute to the extirpation of certain species and/or their habi-
tat.
Passage of the Endangered Species Act of 1973 provided the protec-
tion needed for several species of wildlife to survive. The Act created
a national program that currently involves federal and state govern-
ments, conservation organizations, individual citizens, business and
industry, and foreign governments in a cooperative effort to conserve
endangered wi1dlife.
5.5.5.1 Federal Involvement
The Federal Endangered Species Act of 1973 was amended in 1978 to
direct the Secretary of the Interior and the Secretary of Commerce to
develop plans for the survival and conservation of federally-listed
5-85
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endangered or threatened species. The Secretary of the Interior, acting
through the U.S. F1sh and Wildlife Service has broad authority to protect
and conserve all forms of flora and fauna considered to be 1n jeopardy,
and the Secretary of Commerce, acting through the National Marine
Fisheries Service, has similar power to protect and conserve most marine
life.
An "endangered" species, by definition, 1s one on the brink of
extinction throughout all or a significant portion of its range. A
"threatened" species 1s one likely to become endangered within the fore-
seeable future. Restoring these listed creatures to the point where they
are viable and self-sustaining members of their ecosystems 1s the main
goal of the Fish and Wildlife Service's Endangered Species Program. The
Endangered Species Act also emphasizes the need to preserve critical
habitats on which endangered species depend for their continued
existence. Critical habitats are those areas of land, water and air
space that an endangered or threatened species needs for survival. These
areas include breeding sites, cover and shelter, and surrounding habitat
that provide for normal population growth and behavior. In USEPA Region
IV, critical habitats have been established for several species asso-
ciated with saltwater wetlands. Critical habitat designations affect
strictly federally authorized activities and are made mainly to assist
federal agencies in locating endangered species and in fulfilling their
conservation responsibilities under the Endangered Species Act. Critical
habitats have been established to protect species Including the manatee,
dusky seaside sparrow, and Cape Sable seaside sparrow in Florida. Tables
5-86
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5.5-1 through 5.5-6 present endangered and threatened species listed by
the USFWS by state.
Endangered and potentially endangered species are protected by addi-
tional federal laws including the Migratory Bird Treaty Act, Migratory
Bird Conservation Act, Land and Water Conservation Fund Act, National
Environmental Policy Act, Marine Mammal Protection Act and Fish and
Wildlife Conservation Act. Many states also play a role in conserving
endangered and threatened species. Certain states have entered into
cooperative agreements with the USFWS, making the states eligible to
receive federal financial assistance to improve their conservation
programs.
5.5.5.2 State Involvement
Each state in USEPA Region IV maintains a list of endangered or
threatened species. Included in these lists are species that are asso-
ciated with saltwater wetlands. For the purpose of this report, salt
water-wetland species classified as threatened, of special concern, or
endangered, are species that depend on saltwater wetland habitat for
food, water, shelter and/or reproductive needs during at least some por-
tion of their life cycle. Tables 5.5-1 through 5.5-6 present individual
state lists for saltwater wetland species.
State-listed species of endangered or threatened status may or may
not be protected by state laws or statutes. Certain states lack an ulti-
mate authority with the enforcement capabilities necessary to protect
5-87
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endangered species. The environmental resource agency responsible for
maintaining and updating a state list of species of concern is given by
state for USEPA Region IV in the sections that follow. Most state lists
include those species on the federal 11st 1n addition to endemic wildlife
considered endangered, threatened or of special concern by the
appropriate state officials.
North Carolina
The State of North Carolina has not adopted specific statutory
authority for the protection of endangered species. However, North
Carolina's Wildlife Resources Commission (WRC) has a cooperative
agreement with the U.S. Fish and Wildlife Service for the establishment
of an endangered species program for animals, and the WRC is responsible
for monitoring the effects of proposed projects on these species. The
terms "threatened" and "endangered", as defined by the Endangered Species
Act of 1973, are used to classify the status of North Carolina's species
of concern. The State 11st of endangered and threatened species is
currently the same as the Federal 11st (Table 5.5-1).
South Carolina
The South Carolina General Assembly passed the South Carolina
Nongame and Endangered Species Conservation Act in 1976. This Act
required the South Carolina Wildlife and Marine Resources Commission to
develop a 11st of those species of nongame wildlife endangered within the
state and to conduct programs for the management of nongame or endangered
species. Under this act, 25 species are afforded protection, those that
are associated with saltwater wetlands are Included 1n Table 5.5-2.
5-88
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TABLE 5.5-1
NORTH CAROLINA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Status
Scientific name
Common name
State and Federal
in
oo
vo
MAMMALS
Trlchechus manatus
Pel is concolor cougar
Pel is concolor coryi
BIRDS
Haliaeetus leucocephalus
Pelecanus occidentals carolinensis
Dendrolca ki rt1andfi
Falco peregrinus tundrius
REPTILES AND AMPHIBIANS
Dermochelys corlacea
Alligator mississippiensls
Chelonia mydas
Eretmochelys imbricata
Lepidochelys kempTT
Caretta caretta
FISH
Acipenser brevirostrum
Manatee
Eastern cougar
Florida panther
Bald eagle
Brown pelican
Kirtland's warbler
Arctic peregrine falcon
Atlantic leatherback turtle
American alligator
Green turtle
Hawksbill turtle
Kemp's (Atlantic) ridley
turtle
Loggerhead turtle
Shortnose sturgeon
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Threatened
Endangered
Endangered
Threatened
Endangered
Adapted from: Parker and Dixon, 1980; USFWS, 1982b.
-------
TABLE 5.5-2
SOUTH CAROLINA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Ul
VO
O
Scientific name
MAMMALS
Trichechus manatus
Pel is concolor cougar
Fells concolor coryi
BIRDS
Dendroica kirtlandii
Vermivora bachmanii
Falco peregrinus tundrius
Pelecanus occidental is
Hallaeetus leucocephalus
Aquila chrysaetos
Passerculus sandwichensis princeps
Mycteria americana
Pandion haliaetus
Sterna albifrons
Numenius boreal is
Common name
Manatee
Eastern cougar
Florida panther
Kirtland's warbler
Bachman's warbler
Arctic peregrine falcon
Brown pelican
Bald eagle
Golden eagle
Ipswich sparrow
Wood stork
American osprey
Least tern
Eskimo curlew
Status
State
Endangered
Endangered
Threatened
Threatened
Threatened
Federal
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
REPTILES AND AMPHIBIANS
Alligator mississippiensis
Caretta caretta
Chelom'a mydas
LepidocWelys k'empii
Eretmochelys imbricata
bermochelys coriacea
FISH
Acipenser brevirostrum
American alligator
Loggerhead turtle
Green turtle
Kemp's (Atlantic) ridley
turtle
Hawksbill turtle
Leatherback turtle
Shortnose sturgeon
Threatened
Threatened
Threatened
Endangered
Endangered
Endangered
Endangered
Adapted from:
South Carolina Wildlife and Marine Resources Department Species List; USFWS, 1982b;
Parker and Dixon, 1980.
-------
The South Carolina endangered species program 1s coordinated with
the Heritage Trust Program, which allows donations of land or easements
that constitute endangered species habitat. Authority to protect
wildlife and their habitat is granted through several other acts of
legislation including the South Carolina Coastal Zone Management Act of
1977, Marine Fisheries Laws (1976), Shellfishlng Laws (1976) and the
South Carolina Pollution Control Act.
Georgia
Georgia's State legislature passed an Endangered Wildlife Act in
1973 to protect endangered species. This Act required the Georgia
Department of Natural Resources (DNR) to identify species considered
endangered, threatened, rare or unusual. The first lists of protected
species were approved by the Georgia Board of Natural Resources 1n 1975
and have since been revised (Odom et al., 1977). The classes of protec-
tion are defined as follows:
Endangered species - any resident species which is 1n danger of
extinction throughout all or a significant portion of Its range, or
one which is designated as endangered under the provisions of the
Federal Endangered Species Act of 1973 (P.L. 93-205).
Threatened species - any resident species which is likely to become
an endangered species within the foreseeable future throughout all
or a significant portion of its range or one that is designated as
threatened under the provisions of the Federal Endangered Species
Act of 1973 (P.L. 93-205).
Rare species - any resident species which, although not presently
endangered or threatened as previously defined, should be protected
because of its scarcity.
Unusual species - any resident species which exhibits special or
unique features and because of these features deserves consideration
in Its continued survival in the State.
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The DNR has compiled a list of 23 protected species of wildlife that
may depend on saltwater wetlands at some point in their life cycle (Table
5.5-3). The Endangered Wildlife Act provides that only habitats on
public lands shall be protected (Smith, 1978). Wetland habitat pro-
tection is also afforded by means of the Coastal Marshlands Protection
Act of 1970 and the State Water Quality Control Act which specifically
provides for the consideration of the impact of discharged waters on fish
and wildlife.
Florida
Florida enacted the Florida Endangered and Threatened Species Act of
1977 to provide for research and management in order to conserve and pro-
tect endangered and threatened species as a natural resource. The Game
and Fresh Water Fish Commission (GFWFC) is responsible for research and
management of freshwater and upland species and the Department of Natural
Resources (DNR) is responsible for marine species. Florida has more
endangered and threatened species than any other continental state, and
it is the GFWFC's responsibility to maintain the State Endangered Species
List. Of the 99 species of wildlife listed, 46 species are associated
with saltwater wetlands at some point in their life cycles (Table 5.5-4).
Florida's protected species are defined as follows:
Endangered - any species of fish and wildlife naturally occurring in
Florida whose prospects of survival is 1n jeopardy due to modifica-
tion or loss of habitat, over-utilization for commercial, sporting,
scientific or educational purposes, disease, predation, inadequacy
of regulatory mechanisms, or other natural or man-made factors
affecting its continued existence.
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TABLE 5.5-3
GEORGIA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Status
Scientific name
Common name
State
Federal
t-n
VO
MAMMALS
Trichechus manatus latirostris
Pel is concolor coryi
BIRDS
Til co peregrinus tundrius
Falco peregrinus anaturn
Hali aeetus 1eucocephalus
leucocephalus
Pelecanus occidental is carolinensis
REPTILES AND AMPHIBIANS
Alligator mlsslsslppiensls
Dermochelys coriacea
H1
sT
Eretmochelys imbricata
Lepldochelys kempil
Chelonla mydas
Caretta caretta
FISH
Acipenser brevirostrum
Manatee Endangered
Florida panther
Peregrine falcon Endangered
American peregrine falcon Endangered
Southern bald eagle Endangered
Brown pelican Endangered
American alligator Endangered
Atlantic leatherback turtle Endangered
Atlantic hawksbill turtle Endangered
Kemp's (Atlantic) ridley Endangered
turtle
Green trutle
Loggerhead turtle
Shortnose sturgeon Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Threatened
Endangered
Endangered
Endangered
Threatened
Threatened
Endangered
Adapted from: Odom, et al., 1977; USFWS, 1982b.
-------
TABLE 5.5-4
FLORIDA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Status
Scientific name
Common name
State
Federal
Ui
VO
•P-
MAMMALS
jer avicenma
Sciurus
Oryzomys argentatus
Peromyscus gossypinus allapaticola
Procyon lotor auspicatus
Mustela vison evergladensis
HOT coryi
manatus latirostris
Odocoileus virginianus clavium
licanus occicentalis carolinensis
Mangrove fox squirrel
Silver rice rat
Key Largo cotton mouse
Key Vaca raccoon
Everglades mink
Florida panther
Caribbean manatee
Key deer
Mycteria americana
Haliaeetus leucocephalus
falco sparverius paulus
Falco peregrinus
Charadrius alexandrinus
Grus canad'ensis pratensis
Haematopus palliatus
Florida caerulea
Egretta thula
Dichromanassa refescens
Hydranassa tricolor
Ajaia ajaja
/\ramus guarauna
Sterna dpugal1i i
jterna albifron?
Cistothorus palustris marianae
Cistothorus palustris griseus
Eastern brown pelican
Wood stork
Bald eagle
Southeastern kestrel
Peregrine falcon
tenuirostris Southeastern snowy plover
Florida sandhill crane
American oystercatcher
Little blue heron
Snowy egret
Reddish egret
Louisiana heron
Roseate spoonbill
Limpkin
Roseate tern
Least tern
Marian's marshwren
Worthington's marshwren
Threatened
Endangered
Endangered
Threatened
Threatened
Endangered
Endangered
Threatened
Endangered
Endangered/
Critical Habitat
Endangered
Threatened
Endangered
Threatened
Threatened
Endangered
Endangered
Threatened
Special Concern
Special Concern
Special Concern
Special Concern
Special Concern
Special Concern
Special Concern
Threatened
Threatened
Special Concern
Special Concern
Endangered
Endangered
Endangered
-------
TABLE 5.5-4
(continued)
FLORIDA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Status
Scientific name
Common name
State
Federal
VO
01
BIRDS (cont'd)
Ammospiza maritima m'griscens
Ammospiza maritima mlrabilis
Ammospiza maritima peninsylae
Ammosplza maritima jum'cola'
REPTILES
Crocodylus acutus
Alligator misslssipplensis
Dermochelys conacea
Chelonia mydas mydas
Eretmochelys irobricata itnbricata
LepldocneTys" kempi
Caretta caretta caretta
Klnosternon bauri baurl
Chrysemys conclnna suwanm'ensis
Nerodia fusciata taeneata
Dusky seaside sparrow
Cape Sable seaside sparrow
Scott's seaside sparrow
Wakulla seaside sparrow
American crocodile
American alligator
Leatherback turtle
Atlantic green turtle
Atlantic hawksbille turtle
Kemp's (Atlantic) ridley
turtle
Atlantic loggerhead turtle
Key mud turtle
Suwannee cooter
Atlantic salt marsh water
snake
Endangered
Endangered/
Critical Habitat
Endangered/
Critical Habitat
Special Concern
Special Concern
Endangered
Endangered Endangered/
Critical Habitat
Special Concern Threatened
Endangered Endangered
Endangered Endangered
Endangered Endangered
Endangered Endangered
Threatened
Threatened
Special Concern
Endangered
Threatened
Threatened
FISH
Acipenser brevirostrum
Acipenser oxyrhynchus
Shortnose sturgeon
Atlantic sturgeon
Endangered
Special Concern
Endangered
-------
TABLE 5.5-4
(concluded)
FLORIDA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Scientific name
Status
Common name
State
Federal
FISH (cont'd)
Centropomus undecimails
Menidla conchorum
Fundulus jenkinsi
Rivulus marmoratus
Common snook
Key silverside
Saltmarsh topminnow
Rivulus
Special Concern
Endangered
Special Concern
Special Concern
Adapted from: FGFWFC, 1983; Pritchard, 1979; USFWS, 1982b.
-------
Threatened - any species of fish and wildlife naturally occurring 1n
Florida which may not be in immediate danger of extinction, but
exists in such small populations as to become endangered 1f It 1s
subjected to increased stress as a reult of further modification of
its environment.
Special Concern - any species which warrants special protection
because 1t occurs disjunctly or continuously in Florida and has a
unique and significant vulnerability to habitat modification or
environmental alteration which may result in its becoming a
threatened species.
In addition to the Florida Endangered and Threatened Species Act of
1977, the state has a variety of other laws and regulations designed to
specifically protect species of concern, including the Endangered and
Threatened Species Reward Trust Fund Act, Florida Nongame Wildlife Act,
Florida Panther Act, Florida Manatee Sanctuary Act, Marine Turtles
Protection Act, Bald Eagle Act and Feeding of Alligators and Crocodiles
Act.
Alabama
Alabama has no specific state legislation which establishes protec-
tion for rare and endangered species. However, the Alabama Department of
Conservation and Natural Resources (DCNR) accepts an unofficial list that
resulted from endangered and threatened species symposia held in Alabama
(Boschung, 1976). The unofficial 11st classifies protected species as
follows:
Endangered - species 1n danger of extinction throughout all or a
singificant portion of their range in Alabama.
Threatened - those species which are likely to become endangered
within the foreseeable future throughout all or a significant por-
tion of their range in Alabama.
5-97
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Special Concern - those species which must be continually monitored
because of degrading factors, limited distribution or other physical
or biological characteristics that may cause them to become
endangered or threatened.
These species include not only permanent residents of Alabama, but
also those which may be seasonally dependent on certain areas of Alabama
such as coastal habitats (Table 5.5-5). Wildlife are also afforded pro-
tection by means of the Alabama Water Pollution Control Act and the
Alabama Coastal Areas Act.
Mississippi
The state of Mississippi passed the Nongame and Endangered Species
Conservation Act to manage and protect those species included in the
United States List of Endangered Fish and Wildlife. The Mississippi
Commission on Wildlife Conservation is required to maintain an official
list of endangered and threatened species. The species listed are pro-
tected by state laws regulated by the Commission. The C&mmission defines
an endangered species as one which is in danger of extinction throughout
all or a significant portion of its range; and a threatened species is
one which may become an endangered species within the foreseeable future
in all or a significant portion of its range. Table 5.5-6 reports those
species of State and Federal concern that may potentially occur in salt-
water wetlands at some point in their life cycles.
The Coastal Wetlands Protection Act also assured consideration of
threatened wildlife and their habitat in coastal areas. Projects
affecting the state's water resources also are subject to review in
accordance with the Mississippi Water Resources Act.
5-98
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TABLE 5.5-5
ALABAMA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Status
Scientific name
Common name
State
Federal
t_n
VO
MAMMALS
Trichechus manatus
Sylvilagus palustris palustris
Pel i s concol or coryi
BIRDS
Haliaeetus leucocephalus
Falco peregrinus anatum
Falco peregrinus tundrius
Pelecanus occidental is
Pandion hallaetus
Elanoides forficatus
Lateral!us jamaicensis
Charadrius alexandrinus
Haematopus palliatus
Dlchromanassa rutescens
Florida caerulae
Mycticorax mycticorax
Mycteria americana
Anas fulvigula
Falco colurobarius
REPTILES
AT 1i gator mississippiensis
Lepidochelys kempii
Chelonia mydas mydas
Eretmochelys imbricata
Dermochelys coriacea
Caretta caretta caretta
Manatee
Marsh rabbit
Florida panther
Bald eagle
American peregrine falcon
Arctic peregrine falcon
Brown pelican
Osprey
Swallow-tailed kite
Black rail
Snowy plover
American oystercatcher
Reddish egret
Little blue heron
Black-crowned night heron
Wood stork
Mottled duck
Merlin
American alligator
Atlantic ridley turtle
Green turtle
Hawksbill turtle
Leatherback turtle
Loggerhead turtle
Special Concern
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Special Concern
Special Concern
Endangered
Endangered
Threatened
Special Concern
Special Concern
Special Concern
Threatened
Special Concern
Threatened
Endangered
Endangered
Endangered
Threatened
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Endangered
Threatened
Endangered
Endangered
Threatened
-------
TABLE 5.5-5
(continued)
ALABAMA'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
O
O
Status
Scientific name Common name State Federal
FISH
Aclpenser oxyrhynchus Atlantic sturgeon Threatened
Scaphlrhynchus sp. Alabama shovel nose sturgeon Endangered
Adapted from: Boschung, 1976; O'Nell and Metee, 1982; USFWS, 1982b.
-------
TABLE 5.5-6
MISSISSIPPI'S PROTECTED SPECIES ASSOCIATED WITH SALTWATER WETLANDS
Status
Scientific name
Common name
State
Federal
I
t—*
o
MAMMALS
Trichechus manatus
BIRDS
Grus canadensis pulla
Haliaeetus leucocephalus
Falco peregrinus tundrius
Pelecanus occidental is
REPTILES AND AMPHIBIANS
Alligator mlssissippiensis
Chelonia mydas mydas
Caretta caretta caretta
Lepidochelys kempi
Eretmochelys imbricata
Dermochelys coriacea
FISH
Acipenser oxyrhynchus
Manatee Endangered
Mississippi sandhill crane Endangered
Bald eagle Endangered
Arctic peregrine falcon Endangered
Brown pelican Endangered
American alligator Endangered
Atlantic green turtle Endangered
Atlantic loggerhead turtle Endangered
Kemp's (Atlantic) ridley Endangered
turtle
Hawksbill turtle Endangered
Leatherback turtle Endangered
Atlantic sturgeon Endangered
Endangered
Endangered
Endangered
Endangered
Threatened
Threatened
Endangered
Endangered
Endangered
Adapted from:
Mississippi Department of Wildlife Conservation Bureau of Fisheries and Wildlife,
Public Notice No. 2156; and USFWS, 1982b.
-------
5.5.6 Impacts to Wildlife from Wastewater Application
The wildlife community of a saltwater-wetland ecosystem may be
altered due to managed wastewater application. The potential for change
is dependent on many interrelated biological, physical and chemical
characteristics of the wetland system. Impacts of wastewater on a
wetland also will vary according to how the wastewater system is
designed, installed and maintained, and the type of wastewater that is
applied.
Quantifiable data concerning the wildlife components of treated
saltwater wetlands are not available. However, impacts on wildlife may
be expected to result from altered flow and salinity rates, composition
of vegetation, and the availability of food. The biological, physical
and chemical mechanisms in saltwater wetlands that are involved in
wastewater management are so interrelated that their effects are often
inseparable. Changing the water level and introducing freshwater into a
saltwater marsh may force changes in the vegetative regime. Altering the
species composition within the plant community may, in turn, affect
wildlife species abundance and diversity. Animal populations will change
as a result of food and habitat alterations. The aquatic community also
may be affected by changes in salinity rates due to the addition of fresh
water. Tidal fluctuations and runoff can transport the fresh water,
affecting fish populations. Potential changes 1n the availability of
commercially important fish and shellfish may have economic and
recreational ramifications.
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Discharge of treated effluent from municipal or seafood-processing
waste systems to saltwater wetlands may change the water quality of the
wetland and impact the associated wildlife. The nutrients in the
wastewater increases the productivity of the marsh vegetation and the
nutrient content of the plant tissues. The productivity of the entire
marsh estuarine system could therefore eventually be increased (Fowler et
al., no date). A potential problem from sewage effluent is the con-
centration of materials such as hydrocarbons and heavy metals in the
sediment, which causes a build-up of toxic substances that are detrimen-
tal to productivity (Fowler et al., no date; Hammer and Kadlec, 1983).
The extent of the transfer of metals in the food chain depends upon the
metal, its form, and the extent to which the particular chemical is
translocated to plant parts that are either consumed directly by her-
bivores (mainly insects) or broken down and consumed as detritus. Fish
and filter feeders may absorb metals directly from the water, (Giblin et
al., 1980).
The ultimate fate and effects of introducing toxic substances into
wetlands, the potential for transferring these substances through both
detrital and direct-consumption food webs, and of concentrating them in
sensitive species are not well studied. Some estuarine organisms do have
mechanisms for dealing with high concentrations of metals and other com-
pounds. Hammer and Kadlec (1983) report that oysters can produce
vacuoles of crystalline metal salts that isolate such compounds from
their metabolic system. Crustaceans can transfer environmental pollu-
tants or metabolic by-products into their exoskeleton, which is shed
5-103
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periodically. It is not known whether the pollutants in the chitonous
exoskeleton can be transferred to higher consumers (e.g., fish), since
chitin is not a digestible material (Hammer and Kadlec, 1983). The
question of how much metal contamination can occur before an ecosystem is
damaged remains unanswered.
Wildlife impacts can also occur as a result of absorption by plants
and invertebrates of viral and bacterial pathogens from sewage effluent.
It can only be speculated that viral/bacterial diseases would be
transmitted throughout various levels of the food chain. Long-term stud-
ies in saltwater-wetland systems being used for treated sewage or seafood
processing wastewater application are not available.
There 1s a clear need for information on the effects of wastewater
discharge on saltwater wetlands and wildlife and the potential for trans-
ferring contaminants through food webs. General estimates of beneficial
and adverse effects on wildlife populations and habitats may be Inferred
from freshwater studies and from a few saltwater studies (USACOE, 1977).
Techniques to evaluate the Impacts are being developed. Baseline stu-
dies, conducted prior to a proposed discharge, provide a comparison with
monitoring studies conducted during the discharge Into a saltwater
wetland. Baseline quantitative data also may be derived from state
water-quality monitoring data reports. Other sources of baseline infor-
mation include existing literature reviews, field studies, and/or labora-
tory research. Mathematical modeling and ecosystem simulation can assist
in evaluating assumptions and determining data needs.
5-104
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Biological specimens are often qualitatively or quantitatively
collected and taxonomically identified to establish an ecological base-
line for a given site. Vegetation surveys of wetland areas are useful to
determine existing species, especially any rare and endangered species.
Animal populations can be evaluated through observation and counts (e.g.,
birds), entrapment (e.g., small mammals), tagging (mark and recapture for
fish and wildlife), and sampling (e.g., benthic communities). Fish spe-
cies can be sampled with seines, traps and trawls. Species diversities
are also calculated to determine the "health" of a community or the
effects of wastewater application to a wetland. Field sampling methodo-
logies may be obtained from the literature of the USEPA, U.S. Geological
Survey, and most university libraries. Long-term site specific analyses
would have to be performed to provide the data necessary to assess the
impacts on wildlife of managed wastewater discharges into saltwater
wetlands.
5.6 SCIENTIFIC FACTORS RELATED TO WASTEWATER MANAGEMENT IN SALTWATER
WETLANDS
The saltwater-wetland components described in the previous sections
had several variable and interrelated characteristics, functions and pro-
cesses that could potentially be impacted by municipal or seafood-
processing wastewater discharges. Potential effects could be negative or
positive, depending upon the site and the type of impact being con-
sidered. The unique quality of each wetland is discussed in a review
article which describes five basic orders of magnitude of wetland impacts
and 13 ecological and public-Interest variables that can modify the basic
5-105
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impact (Nelson and Weller, 1984). The authors do not limit their analy-
ses to saltwater wetlands and discuss a broader range of potential
impacts than wastewater discharge alone but the consequences of wetland
alteration that Nelson and Weller describe provide an overview of the
issues discussed here.
A summary of the previous sections 1n this chapter indicates that
there are five major factors to be considered when evaluating the poten-
tial impacts of wastewater discharges In saltwater wetlands: erosion,
nutrients, toxic substances, vegetation and wildlife.
5.6.1 Erosion
Erosion would be expected to vary with characteristics of the soil,
including sediment composition (porosity) and percentage water satura-
tion, with the density of vegetation and with velocity of the discharge
and the method of application. Erosion would probably be most severe 1n
relatively high, sparsely vegetated marshes. Erosion could result 1n
materials washed from one area of the marsh causing sedimentation in
another area; for example, from a high marsh to a low marsh. Conversely,
nutrients in the effluent could stimulate growth of vegetation to the
point where erosion was decreased. Finally, sediments resulting from
erosion that are trapped by vegetation within the marsh may eventually
lead to a change in the species composition of the marsh community.
Areas subject to erosion would require low application levels of
effluent discharge and correspondingly large areas of marsh for erosion
5-106
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control. Rates of effluent application and the amount of marsh area that
would be considered adequate for receiving different effluent volumes are
not known at this time and would require site-specific evaluation.
5.6.2 Nutrients
Treated wastewater would provide a source of nutrients that may have
an effect on wetland marsh vegetation and on the estuarine receiving
waters. The primary consideration regarding nutrients is that the
absorbing capacity of the wetlands not be exceeded. In other words,
nutrients must be taken up by the soil or vegetation prior to tidal inun-
dation. If uptake has not occurred prior to flooding, a wetland
discharge would be equivalent to direct discharge into the estuary.
Nutrient uptake in wetland sediments is dependent on soil sediment
composition and percentage water saturation. Lower marshes are composed
of fine sand, clay and organic deposits, are characterized by a water
table near the surface and are less permeable than the high marshes or
upland soils. Similarly, lower marshes would be inundated by tidal
flooding more frequently and over longer periods of time. It would thus
appear that the higher marshes provide for a greater period of time for
nutrient uptake than do lower marshes. However, site-specific studies
would still be needed to determine sediment characteristics and hydro!o-
gic parameters that could affect the flushing of nutrients from
wastewater effluent into adjacent estuarine waters. Additionally, stu-
dies are required to estimate nutrient uptake by vegetation within the
marsh. Particular emphasis would be on whether nutrients from wastewater
5-107
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effluent would be beneficial, detrimental or of no effect when supplemen-
tal to naturally occurring nutrients.
5.6.3 Toxic Substances and Pathogens
Toxic substances, metals and pathogens are potentially relevant to
municipal and/or seafood-processing wastewater discharges. As occurred
with nutrients, the absorbing capacity of the wetland must not be
overloaded or filtering capacity is lost and it is then equivalent to
direct discharge into the estuary. There are additional concerns with
the toxic substances and pathogens however, that are not of concern with
nutrients. Most of these concerns are related to 1) how metals are tied
up in the sediments or released from the sediments, 2) how metals are
absorbed by plants and transferred through detrital and direct-
consumption food webs, 3) how long pathogens (bacterial or viral) will
remain viable in the sediments and 4) whether pathogens would be absorbed
by plants and/or otherwise passed up the food chain. These questions are
particularly relevant for consideration because they may affect public
health.
5.6.4 Vegetation
Depth and regularity of tidal flooding are the primary factors that
determine vegetation species composition and distribution 1n a salt
marsh; salinity 1s the primary factor in a brackish marsh. Each of these
primary factors may be altered by wastewater discharge to a saltwater
wetland. Potential changes include decreased salinity resulting from the
effluent being primarily freshwater, continual saturation of soil sedi-
5-108
-------
ments, and upsetting the natural seasonal variation in the moisture cycle
within the marsh. Any of these changes could lead to shifts in the marsh
vegetation. For example, if salinity in a saltwater marsh was decreased
for any extended period of time, colonization by plant species adapted to
fresh or brackish-water habitats would be expected to occur. On the
other hand, in a hydrologically-depleted wetland that has been altered by
dikes or channelization, application of treated wastewater could poten-
tially re-establish marsh vegetation, even though it may not be the same
plant species that occurred there originally.
Nutrient uptake by vegetation was previously mentioned as an area
requiring additional study. Vegetation has the potential for removing
and using the nutrients from wastewater and, particularly in areas where
nutrients may be limited, the potential for increased plant productivity.
There is also the possibility that the nutrients added by wastewater
application could extend the growing season, further enhancing produc-
tivity.
5.6.5 Wildlife
One of the potential effects on wildlife of wastewater discharges in
saltwater wetlands would be primarily indirect, resulting from the
altered flow and salinity effects on the vegetation. Animal species com-
position and distribution would be expected to change if vegetation pat-
terns changed because differences would then occur in food availability,
nesting sites, cover and similar habitat parameters.
5-109
-------
Effects on wildlife resulting from toxic substances and pathogens
could be either direct or indirect. For example, pathogens may affect
animals directly, whereas metals would take a more circuitous route
through the food chain. As previously mentioned, several questions are
yet to be answered about the potential effects of toxic substances and
pathogens.
5-110
-------
5.7 LITERATURE CITED
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Boschong, Herbert (ed.) 1976. Endangered and threatened plants and ani-
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York.
Brown and Caldwell Consulting Engineers. 1982. Preliminary design and
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power plants to marine fisheries of the south Atlantic region of the
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-------
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Daiber, F.C. 1972. Tide marsh ecology and wildlife: saltmarsh plants
and future coastal salt marshes 1n relation to animals. 1971-1972
Annual Plttman-Robertson Report to Division of F1sh and Wildlife,
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-------
LITERATURE CITED (continued)
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Hardisky, M.A., R.M. Smart and V. Klemas. 1983. Growth response and
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Lee, C.R., T.C. Sturgis and M.C. Landln. 1976. A hydroponic study of
heavy metal uptake by selected marsh plant species. U.S. Arn\y
Engineer Waterways Experiment Station. Vicksburg, MS. Technical
Report D-76-5.
Lee, C.R., T.C. Sturgis and M.C. Landln. 19765. A hydroponlc study of
heavy metal uptake by selected marsh plant species. Technical
Report D-76-5. Dredged Material Research Program, U.S. Army
Engineer Waterways Experiment Station. Vicksburg, MS. 47 pp. with
tables and appendix.
Linton, T.L. 1968. A description of the south Atlantic and Gulf coast
marshes and estuaries, pp 1-25. lr± J.D. Newson (ed.), Proceedings
of Marsh and Estuary Management Symposium. Louisiana State
University, Baton Rouge.
Long, S.P. and C.F. Mason. 1983. Saltmarsh ecology. Blackie and Son,
Glasgow. 160 pp.
Lugo, A.E. and S.C. Snedaker. 1974. The ecology of mangroves. Annual
Review of Ecology and Systematics. 5:39-64.
Mathews, T.D., F.W. Stapor, C.R. Richter et al., (eds.). 1980.
Ecological characterization of the Sea Island region of South
Carolina and Georgia. Vols. I-III. FWS/OBS-79/40, 41 and 42.
Metcalf and Eddy, Inc. 1979. Wastewater Engineering: Treatment/
Disposal/Reuse. McGraw-Hill. New York.
National Wetlands Technical Council. 1978. Scientist's report.
National Symposium on Wetlands. Lake Buena Vista, Florida, 6-9
November 1978. 127 pp.
Neill, W.T. 1958. The occurrence of amphibians and reptiles in salt-
water areas, and a bibliography. Bulletin of Marine Sciences Gulf
Caribbean 8(1): 1-97. (cited in Sandifer et al., 1980).
Nelson, R.W. and E.C. Weller. 1984. A batter rationale for wetland
management. Environmental Management. Vol. 8, No. 4, Springer-
Verlag New York Inc., New York. pp. 295-308.
Nichols, D.S. 1983. Capacity of natural wetlands to remove nutrients
from wastewater. Journal Water Pollution Control Federation.
55(5):495-505.
Nixon, S.W. 1982. The ecology of New England high salt marshes: a
community profile. U.S. Fish and Wildlife Service, Office of
Biological Services. FWS/OBS-81/55. Washington, D.C. 70 pp.
O'Neil, P.E. and M.F. Mettee. 1982. Alabama coastal region ecological
characterization. Volume 2. A synthesis of environmental data.
U.S. F1sh and Wildlife Service, Office of Biological Services.
FWS/OBS-82/42. Washington, D.C. 346 pp.
5-116
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LITERATURE CITED (continued)
Odum, E.P. 1971. Fundamentals of ecology. 3rd ed. W.B. Saunders
Company, Philadelphia, PA. 574 pp.
Odum, E.P. and A.A. de la Cruz. 1967. Participate organic detritus in a
Georgia salt marsh - estuarine ecosystem, pp 383-388 in G. Lauff
(ed.). Estuaries. American Association for the Advancement of
Sciences. Publication 83, Washington, D.C.
Odum, H.T., B.J. Copeland and E.A. McMahan (Eds.). 1974. Coastal
ecological systems of the United States. Volume II. The
Conservation Foundation and the National Oceanic and Atmospheric
Administration. 521 pp.
Odum, H.T., K.C. Ewel, J.W. Ordway and M.K. Johnston. 1975. Cypress
wetlands for water management, recycling and conservation. Second
Annual Report to National Science Foundation. Center for Wetlands,
Phelps Lab, University of Florida. Gainesville, FL. 817 pp.
Odum, Ron R., J.L. McCollum, M.A. Neville and D.R. Ettman. 1977.
Georgia's protected wildlife. Game and Fish Division, Engangered
Wildlife Program, Georgia Department of Natural Resources, Social
Circle, GA. 51 pp.
Odum, W.E. 1970. Utilization of the direct grazing and plant detritus
food chains by the striped mullet Muqi1 cephalus. In: 0. Steele
(ed.). Marine food chains, a symposium, university "of California
Press, Berkeley, CA. (cited in Sandifer et al., 1980).
Odum, W.E., C.C. Mclvor and T.J. Smith. 1982. The ecology of the
mangroves of South Florida: a community profile. Bureau of Land
Management, Fish and Wildlife Service, U.S. Department of the
Interior. FWS/OBS-81/24. U.S. Government Printing Office,
Washington, D.C. 144 pp.
Odum, W.E., J.S. Fisher and J.C. Pickral. 1979. Factors controlling the
flux of particulate organic carbon from estuarine wetlands. Pages
69-80 in R.J. Livingston, (ed.). Ecological processes in coastal
and marine systems. Plenum Press, New York.
Oertel, G.F. 1975. Post Pleistocene island and inlet adjustment along
the Georgia coast. Journal of Sedimentary Petrology 45(1):150-159.
Oertel, G.F. and J.D. Howard. 1972. Water circulation and sedimentation
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Swift, D.B. Duane, and O.H. Pilkey, (eds.). Shelf sediment
transport: process and pattern. Dowden, Hutchinson and Ross, Inc.,
Stroudsburg, PA.
5-117
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LITERATURE CITED (continued)
01 sen, E.J. 1977. A study of the effects of inlet stabilization at St.
Mary's Entrance, Florida. Pages 311-329 J£ Coastal sediments '77.
Fifth Symposium of the Waterway, Port, Coastal and Ocean Division,
American Society of Civil Engineers. New York.
Parker, W. and L. Dixon. 1980. Endangered and threatened wildlife of
Kentucky, North Carolina, South Carolina and Tennessee. U.S. F1sh
and Wildlife Service and North Carolina Agricultural Extension
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Penfound, W.T. 1952. Southern swamps and marshes. Botanical Review 18:
413-446.
Peterson, C.H. and N.M. Peterson. 1979. The ecology of 1ntert1dal flats
of North Carolina: a community profile. U.S. Fish and Wildlife
Service, Office of Biological Services. Washington, D.C.
FWS/OBS-79/39. 73 pp.
Phleger, F.B. 1977. Soils of marine marshes. Pages 69-77 In V.J.
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Postma, H. 1967. Sediment transport and sedimentation in the estuarine
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Pritchard, D.W. 1967. What is an estuary: physical viewpoint. Pages
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Pritchard, P.C. (Ed.). 1978. Rare and endangered biota of Florida.
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Redfield, A.C. 1967. The ontogeny of a salt marsh estuary. Pages
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5-118
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Rusnak, G.A. 1967. Rate of sediment accumulation In modern estuaries.
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Russell, R.J. 1967. Origin of estuaries. Pages 93-99 jm G.H. Lauff
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Sandifer, P.A., J.V. Miglanese, D.R. Calder et al., 1980. Ecological
characterization of the Sea Island coastal region of South Carolina
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Schelske, C.L. and E.P. Odum. 1962. Mechanisms maintaining high produc-
tivity in Georgia estuaries. Gulf and Caribbean Fisheries Institute
Procedures 14: 75-8. (cited in Sandifer et al., 1980).
Sharp, H.F., Jr. 1962. Trophic relationships of the rice rat, Oryzpmys
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Smith, J.O. 1978. Preservation of endangered species through state law
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Stapor, F.W. and R.S. Mural 1. 1978. Computer modeling of littoral sand
transport (shore-parallel) for coastal South Carolina. S.C. Marine
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Sullivan, M.J. 1971. Distribution and Ecology of Edaphlc Diatoms in the
Canary Creek Salt Marsh. M.S. Thesis. Univ. of Delaware, Newark,
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Taylor, J.L. 1973. Biological studies and inventory for the Tampa
Harbor, Florida project. Taylor Biological Company. 101 pp.
Teal, J. and M. Teal. 1969. Life and Death of the Salt Marsh. National
Audubon Society/Ball antine Books, Inc., New York. 274 pp.
Teal, J.M. and I. Valiela. 1973. The salt marsh as a living filter.
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5-119
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LITERATURE CITED (continued)
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U.S. Fish and Wildlife Service (USFWS). 1982b. Federally listed
endangered and threatened species by state: Alabama, Florida,
Georgia, Mississippi, North Carolina, South Carolina. U.S.
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management. EPA 904/9-83-107. 380 pp.
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and D. Goehringer. 1982. Proceedings of the workshop on ecological
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and D. Goehringer. Unpublished. Some long-term consequences of
sewage contamination in salt marsh ecosystems. Presented at the
Proceedings of the Workshop on Ecological Considerations in
Wetland Treatment of Wastewater, 23-25 June 1982, Amherst, MA.
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Nutrients and particle fluxes in a salt marsh ecosystem: Tidal
exchanges and inputs by precipitation and ground water. Limnology
and Oceanography 23:798-812.
Vernberg, F.J., A. Calabrese, F.P. Thurberg and W.B. Vernberg, (eds.).
1981. Biological monitoring of marine pollutants. Academic Press,
Inc.
Ward, L.G. 1979. Hydrodynamics and sediment transport in a salt marsh
tidal channel. Proceedings of the Sixteenth Coastal Engineering
Conference, ASCE.
Weber, W.J. Jr. 1972. Physicochemlcal Processes for Water Quality
Control. Wiley-Interscience. New York. 640 pp.
5-120
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LITERATURE CITED (continued)
Zedler, J. 1982. Wastewater input to coastal wetlands: management
concerns. Pages 203-216 j_n P.O. Godfrey, E.R. Kaynor and J.
Benforado (eds.). Proceedings of a workshop on Ecological
Considerations in Wetlands Treatment of Municipal Wastewater, June
1982, Amherst, Massachusetts (Draft manuscript).
Zedler, J. 1983. Freshwater impacts in normally hypersaline marshes.
Estuaries 6:346-355.
Zieman, J.C. 1982. The ecology of the seagrasses of South Florida: a
community profile. U.S. Fish and Wildlife Service. FWS/OBS-82/85.
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6.0 ENGINEERING CONSIDERATIONS
Facilities planning, design, and operational con-
siderations associated with discharging wastewater to
a saltwater wetland are discussed in this chapter.
Many of these considerations are similar to those
discussed elsewhere for freshwater wetlands; those
unique to saltwater wetlands are highlighted.
Specific, reliable design criteria for wastewater
loading rates and water depths In wetlands and for
other engineering parameters have not been developed
due largely to the geographic variability of
wetlands, lack of data, and wetland system complexi-
ties. Seafood-processing wastewaters differ from
municipal wastewaters in flow and quality charac-
teristics. The effects of discharging seafood-
processing wastewaters to saltwater wetlands have
apparently not been investigated, judging from infor-
mation collected and evaluated in this effort.
The objective of this chapter is to discuss a wide range of engi-
neering factors relevent to municipalities and industries that discharge
wastewater to saltwater wetlands. Many of these factors are also impor-
tant for freshwater wetland wastewater systems. The reader is referred
to Chapter 6 of the Phase I Report for the Freshwater Wetlands for
Wastewater Management EIS (U.S. EPA, February 1983) for a more detailed
discussion of options suitable for both freshwater and saltwater systems.
Both natural and artificially-created wetlands can be used for mana-
gement of municipal wastewaters. In fact, much more is known about the
design and performance of artificial wetland wastewater systems than
about natural systems. However, artificial systems are less applicable
to saltwater than freshwater wetlands, because little or no research has
been conducted with artificial systems in which salinity or tidal flows
6-1
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have been regulated. Tidal flatlands, however, have been used to create
freshwater artificial systems (U.S. EPA, September 1979).
Sludge management is not included in this report because sludge can
not be discharged to wetland systems due to their designation as "waters
of the United States" (see discussion in Chapter 4.0).
Issues of Interest
What are the engineering considerations important to planning,
designing, implementing, operating, and maintaining a saltwater
wetland for wastewater management?
How applicable is past research with freshwater wetland
wastewater systems to saltwater wetland wastewater systems?
Are specific design criteria for saltwater wetland wastewater
systems available?
To what extent is monitoring of system performance useful?
6.1 MANAGEMENT OF MUNICIPAL WASTEUATERS UTILIZING SALTWATER WETLANDS
In this section planning, design, construction, operation-
maintenance-repair, and monitoring are discussed for secondary-treated
municipal wastewaters discharged to a wetland. The reasons for secondary
treatment prior to discharge are given in Chapter 4.0.
The water quality characteristics of typical secondary-treated muni-
cipal wastewater from a coastal area are listed in Tables 6.1-1 and
6.1-2. Some marine water quality characteristics also are presented in
Tables 6.1-1 and 6.1-2 for comparison with treated wastewater charac-
teristics. Concentrations of metals and organic compounds in treated
6-2
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TABLE 6.1-1
QUALITY GUIDELINES, MARINE WATER QUALITY AND TYPICAL
EFFLUENT QUALITY FOR SELECTED CONSTITUENTS3
Constituent
Most Stringent
Quality
Guideline
Typical
Seawater
Secondary
Effluent
Ammoni a-ni trogen
Cadmium (total)
Chlorine residual
Chlorinated hydro-
carbon (total)
Chromium
Fecal coliforms
Copper
Cyanide
Lead
Manganese
Mercury
Nickel
Phosphorus
(elemental)
Silver
Zinc
270 Q 30°C pH 8.0
3
2
2
2
14 (shellfish)
200 (bathing)
5
5
8
100
0.10
20
0.10
0.45
20
0.1
10
0.5
0.03
2
0.05
7
0.3
10
90
50
10
20
50
2
220
2
260
a All concentrations are in micrograms per liter (ug/1) except fecal coliforms
which are expressed as a number per 100 milliliters.
Quality guideline for un-ionized ammonia is higher at lower temperatures,
lower pH and higher ionic strength. The criterion is to keep unionized
levels below 20 ug/1.
Source of information: U.S. EPA, 1976; Klapow and Lewis, 1979; and Brown
and Caldwell, September 1982.
6-3
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TABLE 6.1-2
PROJECTED EFFLUENT QUALITY FOR OCEAN DISCHARGE
AND APPROXIMATE MARINE WATER QUALITY
Constituent Effluent Receiving Water
Five-day biochemical oxygen
demand (BOD), mg/1a 30
Total suspended solids, mg/1 30
Fecal coliform, MPN/100 ml0 200
Total Kjeldahl nitrogen, mg/1 25
Ammonia nitrogen, mg/1, as
nitrogen 15
Floating solids none
pH Between 6 and 9
Temperature, degrees C Between 6 and 24
Arsenic, ug/lc 2 3.0
Cadmium, ug/1 1 0.1
Chromium, ug/1 25 0.05
Copper, ug/1 - 2.0
Cyanide, ug/1 125
Lead, ug/1 30 NAd
Mercury, ug/1 0.03 0.05
Nickel, ug/1 10 2.0
Silver, ug/1 1.0 NA
Pesticides, ug/1 0.010
Zinc, ug/1 50 NA
a Monthly average, milligrams per liter.
Monthly average, MPN/100 ml equals most probable number per 100 ml.
c ug/1 equals micrograms per liter or parts per billion.
d Not Available
Source: Brown and Caldwell, September 1982.
6-4
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wastewaters can vary widely depending upon the characteristics of
untreated wastewater and treatment efficiency.
In addition, sewage sludge and, to a lesser degree, effluent can
contain toxic metals and pesticides as well as viruses. Pathogens
settled in sediments may be resuspended by physical disturbances such as
dredging (Taylor, 1973). El lender et al. (1980) reported that viruses
can remain infectious in sediments and returned to the water column
through physical or chemical action.
The following factors should be considered in evaluating a wetland
for receiving treated wastewater:
Availability of other reasonable wastewater disposal alter-
natives;
Use(s) of adjacent groundwater and downstream waters (if any);
Impacts of municipal wastewater on vegetation and animal life;
l)se(s) of wetland area: wastewater disposal or wastewater
treatment and disposal, in addition to other uses;
Treatment mechanisms: biochemical uptake-harvesting, adsorp-
tion onto surfaces, gas release (anaerobic for nitrogen), ion
exchange, coagulation;
Types of vegetation within the wetland that can affect wetland
treatment efficiency;
Temperatures within Region IV are favorable for treatment,
although seasonal differences are notable;
Storage of wastewater prior to discharging wastewater to a
wetland can provide wastewater management flexibility;
The benefits of disinfection as compared to cost and other
adverse effects; and
The presence of endangered species or commercially-valuable
species which could be adversely affected.
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No information about achievable treatment efficiency, flow rates, or
other engineering parameters is available for saltwater-wetland systems
in EPA Region IV. Some information for freshwater wetland-wastewater
systems is reported in another EPA document (U.S. EPA, February 1983).
For freshwater wetlands, flows of wastewater per area of affected fresh-
water wetland vary in Region IV from 0.3 to 13 centimeters per week.
Effects of Wastewater on Saltwater Wetlands
If a wetland is to be used to receive treated wastewater, then
adverse impacts need to be controlled and natural processes occurring
within the wetland must be disturbed as little as possible. Potential
impacts and mitigation measures are reviewed by Nelson and Weller (1984).
Wastewater loading rates, water depths, detention time and flow patterns
are factors that can disrupt a wetland system if not controlled.
Some of the impacts of discharging wastewater to wetlands have been
observed, while other impacts are speculative. The major types of
impacts that can occur are listed in Table 6.1-3; whether some or all of
these impacts do occur depends upon the design, installation, and main-
tenance of the wetland wastewater system. Effects also may vary substan-
tially with tidal cycles and on a daily and seasonal basis. No long-term
investigations of these impacts on saltwater wetlands have, however, been
conducted. In general terms, the adverse effects of particular
wastewater constituents are listed in Table 6.1-4.
As discussed in Chapter 5.0 of this report, both positive and nega-
tive impacts on natural ecosystems can result from the addition of
wastewater to saltwater wetlands. Wastewater free of harmful industrial
6-6
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TABLE 6.1-3
POTENTIAL IMPACTS OF WASTEWATER
ON WETLAND ECOSYSTEMS
DOCUMENTED EFFECTS;
Increased plant productivity
Altered species composition within the plant community
Altered animal populations as a result of food and habitat
changes
Altered soil/substrate
Altered elemental content of plants (including nutrients)
SPECULATIVE EFFECTS:
Changes in detrital cycling
Accumulation or transfer of metals, chlorinated by-products and
perhaps other undesirable elements or compounds within the food chain
Transmittal of viral or bacterial diseases at various levels
of the food chain
Changes in salinity levels and ionic strength
Dampening of tidal effects on wetland water levels
Conservation of wetland areas
Potential cost savings if a saltwater wetland can be utilized
Based largely on Table 17 in Hammer and Kadlec, 1983.
NOTE: The effects which have been documented are based on observations in
freshwater wetlands.
6-7
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TABLE 6.1-4
POTENTIAL ADVERSE EFFECTS OF CERTAIN
WASTEWATER CONSTITUENTS
Constituent
Toxic Substances:
1) Heavy metals
(particularly mercury,
copper and zinc)
2) Free Ammonia Nitrogen
(only at pH exceeding 8)
3) Chlorine Residual
4) Chlorinated Hydrocarbons
5) Elemental Phosphorus
(normally oxidized
rapidly to phosphate)
Nutrients
Solids
Bacteria and Viruses
Synthetic Organic Compounds
Detergents
Adverse Effect
Inhibited reproduction or development of
aquatic life forms
Decreased brain or liver activity of
aquatic life forms
Bioaccumulation of certain metals, such
as mercury, in higher levels of food
chain
Gill and liver function and effects of
blood on fish
Fish, shellfish
inhibition
and phytoplankton
Inhibition of respiration/photosynthesis
Carcinogens to mice and rats
Considered to be carcinogenic to humans
Bioaccumulation in fish leading to growth
inhibitions
Acute toxicity to fish and invertebrates
Fish and shellfish toxicity
Bioaccumulation
Possible eutrophication due to excess
productivity
Reduced light penetration
Altered bottom habitat
Diseases transmitted to humans (typhoid
hepatitis and others) *
Accumulation in shellfish
Potential carcinogens
Decreased surface tension
Sensitive to air-water interchanges
Sources: U.S. EPA, 1976; Klapow and Lewis, 1979.
6-8
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chemicals can increase biological productivity in a wetland, if forms of
nutrients which are in limited supply in a wetland are available in
wastewater treatment plant effluent. Improvements in wildlife habitat
have been noted in at least two artificial wetland wastewater systems
(Hammer and Kadlec, 1983). On the other hand, water depths greater than
0.7 meter significantly inhibit the growth of rooted plants which inhabit
the intertidal zone, particularly Spartina alterniflora. The dampening
effect of wastewater on water depth fluctuations resulting from tides
also is discussed in Chapter 5.0.
If dikes, berms, permanent trenches or other modifications are made
to a saltwater wetland, then water circulation would be disrupted. Any
changes to the extent of salinity intrusion inland due to tidal waters
could affect the numbers and types of vegetation and subsequently the
wildlife that exist in a wetland area. Changes in water velocities can
also alter the local ecological community, because different life forms
can prefer different environmental conditions.
If a wetland is being utilized for wastewater management, less
incentive may arise in the future to fill that wetland for residential or
commercial development. The use of a wetland for wastewater management
could therefore help to preserve that wetland. Other benefits are the
additional treatment of wastewater that can occur in a wetland and the
costs savings that could be realized by a potential discharger.
6-9
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6.1.1 Planning and Preliminary Design
Several factors must be considered in order to minimize the adverse
impact of wastewater and to optimize the pollutant removal capability of
a wetland. The factors discussed in this section include wastewater
loading rates, wastewater detention time and flow patterns, water depths,
enhancement of pollutant removal abilities within a wetland, and chlori-
nation.
6.1.1.1 Wastewater Loading Rates
Hydraulic, organic and nutrient loading rates merit consideration in
this study. Depending upon the following factors, one of these loading
rates can govern the design of a treatment facility: desired water
depths, treatment required, detention time of water within the wetland,
vegetation, percolation through soil, temperature, and precipitation.
The loading rate which allows the smallest application of water, organic
material or nutrients to a wetland will govern design and subsequent
activities.
No studies, however, have been found that document impacts resulting
from variations in hydraulic, organic or nutrient loading rates for
wastewater discharged to saltwater wetlands. Furthermore, results of
studies in freshwater wetlands vary with the type of wetland studied,
water movement patterns within the wetland (e.g. significance of soil
infiltration compared to water flowing through a wetland), climate,
season, and differences in measurement and reporting techniques. In a
study at Hay River in Canada, wastewater discharge resulted in a signifi-
6-10
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cant reduction in the diversity of some wetland species. However, in
another study at Great Meadow National Wildlife Refuge in Massachusetts,
no stress was noticed, even though the concentration of pollutants
discharged was similar to the concentration discharged in Canada (Chan et
al., 1982).
The hydraulic loading rates of wastewater discharged to freshwater
wetlands studied in Region IV vary greatly, as shown below (U.S. EPA,
February 1983).
Hydraulic loading,
Location Pre-Treatment ha/m3_day(acres/mgd)
Whitney Park, FL Secondary 0.026 (243)
Wildwood, FL Primary 0.214 (1,997)
Reedy Creek, FL Secondary 0.0054 (50)
Gainesville, FL Package plant 0.0168 (157)
Jacksonville, FL Secondary 0.094 (880)
ha/m3-day: hectare per cubit meter per day
mgd: million gallons (of wastewater) per day
Nutrient loading rates only for short time periods (less than one
year) have been reported for wastewater being discharged to natural
freshwater wetlands in Region IV. For artificial freshwater hyacinth
wastewater systems in warm climates, the loading rates for five-day
biochemical oxygen demand (BOD) and for total Kjeldahl nitrogen (TKN) are
less than or equal to 45 and 13 pounds per acre per day, respectively (50
and 15 kilograms per hectare per day). These reported loading rates are
for systems receiving secondary-treated wastewater (U.S. EPA, February
6-11
-------
1983). Allowable organic loading rates are dependent largely upon the
detention time of wastewater in wetland waters with aerobic conditions.
Nutrient loading rates can differ depending upon the rate of soil and
vegetative uptake of nutrients and, for phosphorus, the extent to which
wastewater percolates through the soil.
From an engineering standpoint, a range of loadings supplemented by
site-specific information is needed as a guideline for planning wetland
wastewater systems and in estimating allowable loadings.
6.1.1.2 Uastewater Detention Time and Flow Patterns
Detention time in wetland wastewater systems is the period of time
wastewater resides within a wetland. Some important wastewater treatment
mechanisms require time, such as removal of suspended solids, oxidation
of organic material (BOD removal) and oxidation of ammonia to nitrate.
If optimizing the pollutant removal ability of a wetland is not a manage-
ment objective, then detention time becomes much less important as a
design factor. Detention time depends upon the volume of water within a
wetland, flow patterns within a wetland, and the flow of water into and
out of a wetland. Detention time in a saltwater wetland will vary quite
radically within a tidal cycle, from season to season or as a result of
storms.
Detention time is estimated by dividing the volume of water within a
wetland by the flow through the wetland, where flow includes groundwater
infiltration and evapotranspiration as well as surface water outflow.
6-12
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This method of estimating detention time is valid for ideal systems, in
which water flows either as a slug or is completely mixed through the
wetland. However, water flowing within a natural wetland often can
follow shorter-than-average flow paths. Use of a tracer dye is one
method to estimate detention time in such non-ideal systems.
6.1.1.3 Wetland Water Depths
Water depth is an important factor in the management of wastewater
within a wetland. Excessive water depths can result in a lack of oxygen
in bottom waters that may adversely impact biological communities. For
artificial freshwater wetland systems, the reported range of water depths
is 0.5 to 3 feet (0.2 to 0.9 meter; Crites, in U.S. EPA, September 1979).
There are no reasons why water depths for natural systems would differ
significantly from water depths for artificial systems. Greater water
depths can increase the removal of suspended solids, but depths greater
than about 4 feet can result in the depletion of dissolved oxygen in bot-
tom waters and sediments (U.S. EPA, May 1975).
Oxygen does not dissolve as well in seawater at equilibrium (6.7
mg/1 saturation at 25"C) as it does in freshwater (8.4 mg/1 saturation at
25*C; APHA et al., 1975). Hence, water depths in saltwater wetlands of
greater than 4 feet could result in depletion of dissolved oxygen in bot-
tom waters and sediments if the waters are not well agitated.
6-13
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6.1.1.4 Pollutant Removal Mechanisms
Wastewater constituents can flow out of a wetland via surface water
or groundwater, volatilize into the atmosphere, remain in marsh biota
and/or sediments, or be chemically or physcially converted during resi-
dence in the wetland.
Of the various physical and chemical pollutant removal mechanisms
shown in Table 6.1-5, decomposition, adsorption and sedimentation are
often the most important. If significant groundwater recharge takes
place, filtration can also become important. Adsorption and decom-
position are important, particularly in warm climates, because of the
high biological productivity and large amounts of suspended material
found in saltwater wetlands. Sedimentation can be important if water
velocities are low. As solids settle, particle sizes often increase in
the saltwater column due largely to the high ionic strength of brackish
waters (Edzwald et al., 1972).
Aquatic plants can enhance pollutant removal, although plants that
float or are submerged without roots and thus can extract nutrients
directly from the water column are more common in freshwater wetlands
than saltwater wetlands. Harvesting of aquatic plants has been tested in
some artificial wetland systems as a method to enhance plant production
thereby enhancing nutrient removal. All aquatic plants also provide
sites for bacteria that biochemically degrade organic matter to residue.
6-14
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TABLE 6.1-5 PHYSICAL AND CHEMICAL POLLUTANT REMOVAL MECHANISMS IN WETLAND AND AQUATIC SYSTEMS
tn
Pollutant affected
M
*s - - il « e
~u "oi» "c 3 *P P £ "•
Hechantsn *1 gg ^J gfi 5 |
Hwlcal
Evaporation X X
Sedimentation XX XX
[•vilification XXX
Adsorption X X X
Filtration X X
Chemical
CKtlatlo* X
Precipitation X X
Decomposition X X X X
Chenical adsorption X X X X
! li !!
5 S"J 5S Description
X* X Volatllliatlon and aarotol
fomatlon
Ik i Gravitational tattling of
particles and adsorbed
pollutants
X* X Suspension of chemicals
that are sparingly soluble
In water vtthln M aque«vi
envlroDBMt
X i X Electrostatic attraction.
Van dcr Haals force
1 Nechanlcat filtration of
particles through substrate.
roots or anlnal system*
X Fematlon of metal com-
plexes through llgands
X Formation of or copreclplta-
tlon nf Insoluble rameninils
XX X Alteration of less stable
compounds by oildatlon. re-
duction, hydrolysis or
photochemical reaction
X X Covalent bonding, hydrogen
bond formation, oydropteblc
Interaction
a. !>i»nlfleant only for Btrcury.
b. Not significant for wnganasa a«d mtrcmy.
Reference: Chan, et al. 1982
-------
Decomposition is particularly affected by water temperature.
Average temperatures within Region IV states are typically high enough to
allow for decomposition. The climate in the southeastern United States
also promotes long vegetative growth periods, which can be advantageous
for enhancing wastewater renovation processes. Because plants and other
life forms are dormant during winter months, wastewater assimilation by
plants should be supplemented by other treatment methods or storage capa-
city if nutrient removal during winter months is an important objective.
Removal of pollutants by physical processes, such as sedimentation
or soil adsorption, is also affected by seasonal changes but to a lesser
extent than is biological conversion of pollutants. Therefore, wetland
wastewater systems that rely on physical processes can more easily be
designed for year-round operation than can systems relying on biological
processes.
Significant questions remain regarding pollutant removal efficien-
cies as a function of time, the effects of ionic strength, temperature
and biota, and the long-term ability of any wetland to remove wastewater
constituents. Saltwater wetlands have unique water circulation charac-
teristics due to their unique topographic nature. With large amounts of
flushing of saltwater wetlands during a tidal cycle, the ability of a
wetland to renovate wastewater can be limited because of limited water
retention times. Treatment kinetics vary depending upon the con-
centration of constituents, temperature, ionic strength and biochemical
activity. One wetland may be better suited to utilizing a certain
6-16
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wastewater constituent (e.g. nitrogen) than another wetland. Long-term
renovation is a question which has been addressed only in a few projects
involving freshwater wetlands. Constituents which settle, adsorb or
filter out of solution are usually stored within the wetland. Eventually
enough material could be stored so as to alter the wetland system. No
significant adverse effects on wetland ecology have been observed in the
few freshwater wetland wastewater systems that have received secondary-
treated wastewater for 3 to 5 years or longer.
Site-specific data that could be collected to evaluate the potential
of a wetland to be used for wastewater management are shown in Table
6.1-6.
6.1.1.5 The Need for Chiorination
Traditionally, wastewater is disinfected prior to being discharged
in order to reduce the possibility of public health problems. However,
wetlands have been shown to be able to assimilate bacteria and other
microorganisms. Furthermore, some concern exists about the effects of
chloramines (a by-product of chlorine and ammonia from wastewater) and
chlorine remaining in the wastewater when discharged. In this regard,
the available options are: use of chlorine, use of another disinfectant
such as ozone or ultra-violet light, use of chlorine followed by dech-
lorination (via pond retention or sulfur dioxide), or no disinfection.
The option of no disinfection is less costly and avoids safety concerns
with chlorine use but may result in adverse public health impacts
depending upon: (1) individual wetland characteristics and accessi-
6-17
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TABLE 6.1-6
COLLECTION OF SITE-SPECIFIC DATA FOR EVALUATION
OF A WETLAND FOR WASTEWATER TREATMENT
Water Budget
Annual precipitation, cloud cover and radiation data acquisition
Stream-flow data
Water level records for wetland and adjacent water bodies
Subsurface flow patterns
Surface elevation survey
Overland flow patterns
Tidal effects on flows and water levels
Seasonal Water Quality
Nitrogen, phosphorus, chloride
Coliforms, BOD, suspended solids, TDS, etc
pH, temperature, conductivity
Soil Processes
Type and depth of peat, detritus
Ion exchange capacity of peat
Permeability (hydraulic conductivity)
Flora and Fauna
Algae inventory
Plants - cover map, identify endangered species, nutrient status
Invertebrate inventory
Use Patterns
Vertebrates (e.g. reptiles, mammals, and birds)
Human
oource of selected information: Hammer and Kadlec, 1983
6-18
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billty; (2) variations in those characteristics with time; and (3)
constraints of existing state water quality classifications, such as for
shellfish waters.
Dechlorination following chlorine disinfection can remedy potential
problems with chlorinated by-products while still allowing disinfection
to take place. Dechlorination can be accomplished by retaining
chlorinated wastewater in a shallow pond during daylight hours prior to
release to the wetland or by utilizing sulfur dioxide. Pond retention
requires much less operation and maintenance, however !and requirements
are much greater than for addition of sulfur dioxide.
6.1.1.6 Mathematical Modeling of a Wetland as a Planning Tool
To be utilized as a planning tool, a model would need to simulate
wetland hydrology and perhaps water quality in such a way that discharge
permit requirements could be established. Such a hydrologic or water
quality model would need to be able to predict water circulation patterns
and water quality processes, by solving mathematical equations simulat-
neously for numerous sections of the wetland.
Models have been developed which simulate water budgets for a par-
ticular wetland area (as reported in U.S. EPA, February 1983).
Ecological processes have also been simulated. One problem is that
separate models are needed for each wetland which makes the evaluation of
hydrology and water quality for a number of wetland areas very time con-
suming and costly. A second problem is that a large amount of field data
is needed before a model can be utilized.
6-19
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As reported by U.S. EPA (February 1983), different states in
EPA-Region IV utilize different types of models to assess discharge per-
mit requirements. Most models utilized by state agencies are based on
models utilized for streams and rivers; the problem with these models is
that flow within a wetland is lateral as well as longitudinal.
6.1.2 Design of Municipal Systems
Design considerations incorporate a finer level of detail than what
is necessary for planning. The design items addressed in this section
are wastewater circulation patterns, costs, energy and chemical usage,
and additional considerations. Design considerations are also provided.
6.1.2.1 Wastewater Circulation Patterns
While many points of discharge can be considered in a wetlands
alternative, wastewater is typically released at the edge of a wetland
and as close to the wastewater treatment plant as possible. The decision
of where to locate a discharge is usually based on cost considerations.
Discharge sites can be located at the edge of a wetland, or within
the interior of a wetland away from homes or valuable wetland habitat.
Costs and the ease of obtaining pipeline right-of-way are important fac-
tors that could affect the feasibility of a discharge within the interior
of a wetland. A single pipe or channel, multiple pipes, multiple ports
from one pipe, or sprayers can be utilized to release wastewater to a
wetland. A decision concerning each discharge location should be made
independently based on that wetland's flow paths, vegetation types, vege-
tation densities, erosion potential and pollutant removal potential.
6-20
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Table 6.1-7 presents the advantages and disadvantages of four types
of discharge configurations in terms of costs, impacts on the environment
due to pipeline (or channel) placement, and maintenance. Releasing
wastewater in a way that significantly alters natural flow patterns
within a wetland is not recommended. Better matching of discharge rates
to natural flow patterns can be obtained by using storage ponds at or
adjacent to the wastewater treatment plant to regulate flows of waste-
water entering a wetland.
Artificial control of water circulation has been instituted only
with artificial wetlands. Artificial flooding and control of water
depths would be much more difficult to implement effectively in saltwater
wetlands than in freshwater wetlands, because saltwater wetlands are
affected by tidal influences. Outlet flows from a saltwater wetland can
not be artificially controlled without also affecting water salinity and
hence affecting the entire wetland ecosystem.
6.1.2.2 Costs
In general, the more costly activities are the ones that would
affect wetland ecosystems most significantly, such as harvesting vegeta-
tion or using physical structures to control flow paths within a wetland.
The use of wetlands for wastewater management can be cost effective.
Tchobanoglous et al. (U.S. EPA, September 1979), Sutherland (in U.S. EPA,
1979) and others have demonstrated that the use of freshwater wetlands
for wastewater treatment beyond the secondary level can be significantly
less costly than conventional treatment processes.
6-21
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Table 6.1-7 Effluent Application Configurations.'
Advantages
Effluent Applications
Configurat ions
Disadvantages
Comment s
CT>
l
ro
ro
Point Discharge at edge
of wetland, gravity flow
Channel discharge at
edge of wetland,
gravity flow
Distribution within
wetland, gravity flow
Distribution within
wetland, spray flow
Low Cost
Low 0§M requirements
Low energy use
Can be installed with minimal
impacts to a natural wetland
- Low 05M requirements
- Installation impacts limited
to edge of wetland
- May provide some dechlorination
within channel (cascade affect)
- More uniform distribution than
point or channel discharge
- Relatively low 05M require-
ments (no moving parts)
More uniform distribution
than point or channel
discharge
May provide some dechlorination
Low erosion potential via
spraying
Often poor or unknown
distribution of wastewater
Erosion and channelization may
occur if wastewater velocity
is high
Solids may accumulate near
discharge if wastewater
velocity is low
Often poor or unknown dis-
tribution of wastewater
Erosion or channelization may
occur if wastewater velocity
is high
Solids may accumulate near
discharge if wastewater
velocity is low.
Installation impacts to
natural wetlands
Installation costs
Aerosols may cause public
health impacts
Energy required
Nozzles may clog unless pre-
treatjaent includes fine
screening
06M requirements higher than
for other alternatives
Installation impacts to natural
wetlands
Installation costs
Distribution may be improved by selection
of discharge point to take advantage of
natural flow paths, increasing the number
of discharge points, or enhancing mixing
within the wetland by mechanical or
physical devices
Erosion control techniques are available.
Concrete or grass-lined channel aay be used
Erosion control techniques are available
Distribution may be accomplished by pipe
outfalls at a variety of points within
wetland, or by perforated or gated pipes
Pipes can be installed on the surface,
buried or elevated
Surface pipes will have lesser installa-
tion impacts and costs but will have
greater 06M requirements
Piping may be laid on the surface, buried
or elevated
Surface piping will have lesser installa-
tion impacts and costs but will have
greater 0§M requirements
1. U.S. EPA, Assessment of current information on overland flow treatment of municipal wastewater, May 1980.
-------
To Install a wastewater outfall 1n a wetland area, four examples of
costs have been estimated for the following wastewater disposal options:
a. A channel, 500 feet in length, to the edge of a wetland
(grass-lined with gates; no supplemental pumping);
b. A buried pipe through 500 feet of dry soil. Assume that no
rock and no significant soil freezing are encountered and that
no significant pumping of wastewater is required.
c. Same as (b), above, except that the buried pipe traverses 500
feet of soil where the water table is at the soil surface (wet
soil).
d. The same as option (b) except that two 500-foot pipes (within a
wetland) extend in the wetland in different directions.
Sprayers are located at the end of each of these two buried
pipes.
Costs have not been included for land acquisition or wastewater storage
ponds. Operation, maintenance and repair costs for pipelines and
sprayers have also not been included, but such costs would be low for 500
to 1,000 feet of pipe over a 30 to 40-year service life. The service
life of a pipeline may be shorter in a saltwater wetland than in a fresh-
water wetland due to saline soil conditions.
The following assumptions have been used in this cost analysis:
Costs are in second quarter, 1983 dollars for Atlanta, 6A
(Engineeing News Record construction cost index = 4003);
Excavating, dewatering, and backfilling costs are included as
well as costs for engineering, construction supervision and
contingencies;
Channel costs are based on a 3.5 foot channel depth and a 1:2
channel side slope;
Pipelines are assumed to be buried approximately 1 foot below
the soil surface;
For dry soil excavation, a crawler-mounted backhoe can be uti-
lized. Costs can vary depending upon the type of soil being
6-23
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excavated, but a typical cost of $4 per cubic yard was
utilized; and
For wet soil excavation, a dragline was assumed to be utilized
for excavation. Typical costs are $5 per cubic yard. No
additional costs were included to account for intermittent
installation. Trench dewatering, if needed, would only
increase the total capital costs by approximately $500.
Table 6.1-8, which gives results of the cost estimates, shows that,
for 1 million gallons per day (MGD) capacity, a channel is the least
costly method of installation, followed by buried pipeline. Costs for
excavation and pipeline installation in wet soils are basically the same
as costs in dry soils. The use of sprayers to distribute wastewater once
it reaches the termination of the pipeline adds approximately $6,000 of
costs per sprayer for capacities of 1 to 5 MGD of wastewater. The use of
wooden supports more than doubles the cost of transporting wastewater to
a wetland area, based on costs encountered at Houghton Lake, MI (updated
to 1983 cost indices). Capital costs for providing chlorination far
exceed costs for transporting wastewater a reasonable distance away from
human populations, even without considering the significant operating
costs for chlorination.
6.1.2.3 Energy and Chemical Usage
Operation of any wetland-wastewater system could require energy for
the following uses: wastewater pumping, wastewater spraying, utility
vehicle(s) for monitoring and maintenance, and harvesting of vegetation.
All of these energy-using operations may be avoidable except perhaps the
utility vehicle(s). Pumping requirements would be relatively small,
because wetland elevations are lower than nearby upland elevations.
6-24
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TABLE 6.1-8
SUMMARY OF EXAMPLE
WASTEWATER DISPOSAL CAPITAL COSTS
Capital Cost, $
(ENR1 = 4003)
A) Man-made channel 500 feet in length:
1) Wide-bottom, grass-lined ditch (for 1 mgd capacity) 8,000
2) Wide-bottom, grass-lined ditch (for 5 mgd capacity) 30,000
B) Piping - single pipe through 500 feet of dry soil
1) 12" diameter (for 1 mgd capacity) 11,000
2) 24" diameter (for 5 mgd capacity) 14,000
C) Piping - single pipe through 500 feet of wet soil (costs
do not include artificial dewatering; installation may
need to take place during periods before and after low
water slack.) i?\
1) 12" diameter (for 1 mgd capacity) 11,100 27,000)«<
2) 24" diameter (for 5 mgd capacity) 14,000 29,000vt;
D) Piping - dual plastic pipes each extending 500 feet in
wet soil with sprayers to distribute wastewater
12" diameter (for 1 mgd capacity) 35,000 G
24" diameter (for 5 mgd capacity) 40,000 72,000
we i
\)
E) Chlorination
1) For 1 mgd capacity 105,000
2) For 5 mgd capacity 221,000
* ' ENR refers to the Engineering News-Record Construction Cost Index.
(2)
v ' If pipeline is supported on or above the soil surface by wooden supports
rather than buried beneath the soil surface.
Sources of information: Robert Snow Means Co., 1983; U.S. EPA, February 1980; and
Hammer and Kadlec, 1983.
6-25
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Harvesting of vegetation within a natural, saltwater wetland is not known
to have been attempted on a long-term basis; concerns exist about adverse
environmental impacts as well as energy and labor requirements.
The amount of fuel utilized by a utility vehicle would depend upon
the size of the wetland and the extent of monitoring and maintenance
activities.
Use of a wetland for wastewater management is a natural process,
while conventional wastewater treatment processes often require aeration,
mixing chemical addition and perhaps supplemental heat to operate effec-
tively. A conventional wastewater treatment process is, therefore, more
energy intensive than is treatment provided in a natural wetland.
6.1.2.4 Design Considerations
Many important planning concerns must also be considered in the
design and installation of a wastewater project involving wetland areas.
These design considerations include:
Determination as to whether supplemental wastewater treatment
is to be included as a wetland design objective;
Estimates of wastewater detention time, water circulation pat-
terns, water depths and (if needed) treatment kinetics for a
wetland area;
Weekly and seasonal variations on biological activity (e.g.
flooding, drought, winter slowdown);
Need for chlorination or another form of wastewater disinfec-
tion, followed by a cost assessment, if a need exists;
Need for supplemental wastewater storage volume, followed by
a development of sizes and costs for storage facilities, if a
need exists;
6-26
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Precise locations(s) of wastewater outfall;
Specific method of wastewater discharge (end of pipe, diffuser
pipe, sprayers and choice of materials);
Method of placing pipeline;
Operation and maintenance activities anticipated after
installation;
Contingency plan in case of unusual problems or upsets;
Overall costs vs. benefits of wastewater discharge system;
Need for pilot-scale facility;
Plan for effective system installation; and
Plan for phasing in discharge activities following installa-
tion.
In order to effectively address the above stated concerns, persons
familiar with the local wetland hydrology and ecology should be consulted
as the wastewater storage and pipeline facilities are designed and
installed.
Additional design concerns that may need to be considered include
the following four points. First, a quantitative mass balance for each
pollutant to be treated within the wetland may need to be considered. By
knowing the quantities entering a wetland and estimating treatment effi-
ciencies, quantities leaving a wetland can be estimated and later checked
when the system is in operation. The mass balance estimates may vary
because of seasonal variations. Mass balance estimates may also vary
over a longer time frame (e.g. 10 to 15 years) if pollutants accumulate
within a wetland and are eventually released.
6-27
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Secondly, variability among equipment manufacturers may need to be
recognized. Certain manufacturers may provide types of equipment that
are more suitable for wetland alternatives than other manufacturers (e.g.
sprayers, diffuser pipes). Less frequent maintenance is preferred for
facilities located within a relatively inaccessible wetland even if costs
for less frequent maintenance are somewhat higher. Plastic or aluminum
pipe should be suitable for the saline, somewhat corrosive environment of
a saltwater wetland.
Third, specifications for installation may be developed which
include requirements to minimize the impacts of construction on wetlands.
Examples of possible specifications are the following:
Installation could be restricted to a certain season;
Excavated soil can be replaced to original contours following
installation; and
Specific equipment requirements can be dictated.
Fourth, a contingency plan should be considered in case of extreme
weather conditions, treatment plant failures, or sudden changes in
wastewater characteristics. As mentioned earlier in this section,
wastewater can be stored or an alternative method of emergency wastewater
disposal can be utilized. Control of extreme water levels or excessive
erosion is nearly impossible in a saltwater wetland, because upstream
flows are often very large, and outlets to coastal waters occupy a large
geographic area.
6-28
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The following design guide and checklist for aquatic systems (Table
6.1-9) adopted from Stowell et al. (1980) summarizes important design
considerations for wetland alternatives.
6.1.3 Installation and Operation-Maintenance-Repair
Installation is usually conducted so as to minimize costs to the
contractor. Hence, any environmental requirements during installation
need to be included in the written contract specifications supplied to
the bidding contractors. Examples are given in Section 6.1.2.4. Various
methods have been utilized in freshwater wetlands on an experimental
basis to minimize disturbances due to installation. Unnecesary soil com-
paction can be avoided. Pipelines can be suspended on a trestle-like
structure above the wetland. Installation can be conducted during
periods of the year when the local wildlife are not particularly
vulnerable (e.g. avoiding installation during annual breeding periods).
When working in a wetland, construction inspectors could be employed who
are aware of the potential environmental impacts of various activities as
well as the problems associated with activities performed in saturated
soils. Otherwise, a failure of at least a portion of the wetland system
to survive could occur as a result of installation activities.
The most important design decision, from the installer's perspec-
tive, is whether the wastewater is to be released from a channel, or
piped above or below ground. Channels require more maintenance than
pipelines, but pipelines above the ground surface are susceptible to
storms, cold temperatures, animals and other external effects. Pipelines
6-29
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TABLE 6.1-9
DESIGN GUIDE AND CHECKLIST FOR WETLAND-WASTEWATER SYSTEMS
Preliminary Investigation
1. Survey sites suitable for a wetland-wastewater system in terms of current
uses, water quality standards and discharge requirements.
2. Review and summarize climatic and hydrologic factors: temperature,
precipitation, and wind; flow paths and water levels during flood and ebb
tide; vulnerability to coastal storms.
3. Survey local flora: growth season, vegetative structure through winter,
and potential to affect aquatic environments to evaluate effects of
wastewater on vegetation (including ability of vegetation to uptake
nutrients).
4. Review discharge requirements: are seasonal requirements possible if
justified?
5. Review literature with emphasis on type of project being envisioned,
contaminant removal mechanisms, and treatment performance and reliability.
6. Formulate preliminary aquatic system design, including use of conventional
treatment processes and use of disinfection.
7. Analyze cost effectiveness of alternative wastewater treatment processes:
go or no-go aquatic system design.
Aquatic System Design
1. Itemize expected flows, influent concentrations, and discharge
requirements.
2. Identify contaminant removal mechanism(s) and environment(s). (Complete
this analysis for each contaminant to be removed if treatment of
wastewater within a wetland is important or if particular industrial
wastes raise concerns.)
a. Removal mechanism(s).
1. Identify removal mechanism(s) operative on contaminant of
concern.
2. Summarize kinetics of removal mechanism(s) and factors affecting
the kinetics: contaminant concentration, temperature, pH, etc.
b. Aquatic environment(s) required for removal mechanism(s) to be
operative.
1. List requirements for aquatic environment(s).
2. List factors affecting these requirements: climatic factors,
organic loading rate, plant species, chemical and equipment
input, etc.
3. Determine precise location(s) of wastewater discharge and type of
distribution system.
a. What components necessary to the aquatic environment will it provide?
b. Seasonality in the local environment?
6-30
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TABLE 6.1-9
(continued)
DESIGN GUIDE AND CHECKLIST FOR WETLAND-WASTEWATER SYSTEMS
c. Local diseases and predators: seasonal or year round?
d. Nuisance potential?
e. Chemical and equipment input.
1. What components necessary to the aquatic environment will it
provide?
2. Continuous, seasonal, or emergency use?
f. Management options to maintain aquatic environment (e.g. harvesting).
g. Rate of contaminant removal (if treatment of wastewater within the
wetland is important) surface area requirements on a seasonal basis.
4. Design aquatic system.
a. Are the discharge requirements met?
b. What measures can be taken to increase the reliability of the system?
c. Complete quantitative mass balance (in terms of removal mechanism
kinetics) for each contaminant for the seasons of the year, if
treatment of wastewater within the wetland is important.
d. Management.
1. To maintain the system.
2. Courses of action in cases of system upset: contingency plan.
5. Make final check on cost effectiveness of aquatic system.
6. Possibly design and operate pilot scale facility. (This step is necessary
if contaminant removal mechanism rates and factors affecting these rates
are to be quantified. If the pilot does not function as anticipated,
aquatic system design steps 2 through 6 will have to be modified as
necessary. Failure of the pilot facility could result in the wetland
disposal alternative being dropped from consideration.)
7. Design and construct full-scale aquatic system. Include any
specifications which are considered important in limiting the freedom of
the installer to concentrate solely on minimizing installation costs.
Adapted from Stowell et al., 1980
6-31
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below ground are susceptible to differential soil movement in some
wetland areas. For wetlands with firm substrates a "push-ditch" method
for burying pipeline causes temporary turbidity from the dredging opera-
tion but once the pipe is installed and backfilled, the impacts subside
(Conner et al., 1976). Environmental impacts from installation are less
significant for above-ground pipelines. All three methods of
transporting water have been utilized in wetland systems.
Proper operation, maintenance and repair are vital, because failure
of a wetland to assimilate wastewater could result in adverse effects on
the natural, saltwater wetland. Good planning, design and installation
can be negated by improper operation, maintenance or repair.
Important operation, maintenance and repair can include: (1)
controlling the quantity and quality of released wastewater; (2) altering
water flow paths within a wetland, if appropriate; and (3) controlling
the quantities of living vascular plants; and (4) pipeline maintenance.
The third and fourth types of activity are more costly to conduct than
the first two.
Flexibility should be incorporated into the design and construction
of a project. If wastewater storage facilities and/or alternative
wastewater disposal techniques have been designed and installed, opera-
tion can be more flexible than if these options for controlling
wastewater flows are not available. Water flow paths can be altered if
alternative locations for releasing wastewater to a wetland are
available, if dikes are in place, or if sediments within a wetland are
6-32
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allowed to be dredged. Aquatic plants can be controlled by physical har-
vesting or the use of herbicides or biological controls; vegetation can
be increased by seeding or planting portions of a wetland.
Methods for promoting proper operation, maintenance and repair are
available:
Operating requirements of the wetland wastewater system can be
combined with treatment plant operations. A combined
operation-maintenance-repair manual for the treatment plant and
the wetland can be developed. In addition, the same personnel
can be responsible for both the operation of the treatment
plant and the wetland.
Manufacturers can provide recommended periodic maintenance
intervals for equipment (e.g. for sprayers).
Periodic inspection can be conducted in conjunction with a
monitoring program.
6.1.4 Monitoring
Effluent and wetland monitoring can be required as part of a
municipality's NPDES (National Pollutant Discharge Elimination System)
permit. Monitoring at various stages within the wastewater treatment
plant could also be required. The municipality could be asked, possibly
with the help of a wetland specialist, to propose an ongoing monitoring
program as part of its NPDES permit application. Once the contents of
the monitoring program are agreed upon and implemented, periodic moni-
toring results could be presented to the responsible state agency for
review. Modifications to the program may be developed as results are
used to help assess the impact of the wastewater on wetland use and func-
tion.
6-33
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Possible elements of a monitoring program are the following:
a. What to monitor: water levels, pH, dissolved oxygen, specific
conductance, suspended solids, five-day BOD, coliform bacteria,
alkalinity, nutrient levels, biological indicators, vegetation.
b. Where to monitor:
Upstream of the wastewater discharge within the wetland,
the wastewater itself, downstream of the discharge within
the wetland (perhaps at a number of locations), and
downstream of the wetland itself as appropriate (e.g.
estuarine waters).
Surface water, sediment, groundwater, various locations
within wastewater treatment plant.
c. When and how often to monitor:
Daily, weekly, monthly, seasonal
Before, during and/or after a rainfall event
Low-flow, average-flow and/or high-flow period
Ebb tide, slack, and flood tide
Different times of day (important to biochemical reactions)
d. How to monitor: procedures with reasonable logistics and moni-
toring effectiveness may be needed for each wetland wastewater
system.
e. Equipment, field procedures, laboratory procedures and
reporting procedures.
These monitoring elements are listed only to show the broad range of
monitoring possibilities. Specific decisions about what, where, when,
how often and how to monitor will differ for each wetland wastewater
system as agreed to by the municipality and the responsible regulatory
agency. The extent of monitoring that is considered worthwhile will not
be well understood until wetland characteristics have been defined
through field efforts.
6-34
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Treatment plant operations, variations in wastewater charac-
teristics, and changes in upstream areas will be important to note during
monitoring. Any significant variation in wastewater loadings can upset
the natural tendency for wetlands to equilibrate. During periods of
upset, a wetland is most prone to adverse environmental effects.
6.2 MANAGEMENT OF SEAFOOD-PROCESSING UASTEUATERS UTILIZING SALTWATER
WETLANDS
Many of the concepts covered in Section 6.1 for municipal wastewater
also apply to seafood processing wastewaters. However, instead of secon-
dary treatment of seafood wastewater prior to discharge to a wetland,
Best Conventional Pollutant Control Technology (BCT) is a pre-requisite.
In addition, wastewater flows from seafood processors can be extremely
irregular unlike flows from most wastewater treatment plants. The
effects of seafood processing discharges on wetland areas have not been
documented, primarily because very few seafood-processing discharges
released to wetland areas have been studied.
This section discusses those aspects of discharging seafood-
processing wastewaters to a wetland that differ from those of municipal
wastewaters.
Issues of Interest
How do seafood-processing wastewaters differ from municipal
wastewaters?
How do the effects of seafood-processing wastewater discharges
differ from those of municipal discharges?
6-35
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6.2.1 Planning and Preliminary Design
A number of variables are evident when considering the discharge of
seafood processing wastes:
Types of seafood processed: shrimp, crabs, clams, oysters,
fish, or a combination;
Types of processing: peeling, sorting, thawing, cleaning,
fileting, meal processing, breading;
The type of processing performed at a seafood plant depends
upon the extent of processing done aboard the fishing vessels;
Quantities of fish and shellfish that are processed, which vary
seasonally, weekly and daily;
The extent that house-cleaning activities are conducted at a
seafood processing plant (i.e., solids being washed into floor
drains instead of being placed in garbage cans); and
Adequacy of wastewater treatment processes associated with the
seafood processing facility.
Figure 6.2-1 outlines the typical steps in preparing seafood for market.
Brinsfield and Phillips (1977) present data from 1975 and 1976 for
18 seafood processing facilities in Maryland that show very high residual
chlorine concentrations (30 to 90 mg/1) and simultaneous mean total coli-
form levels exceeding 1,000 per 100 ml (a typical standard for median
total coliform levels in shellfish waters is 70 organisms per 100 ml).
Brinsfield and Phillips (1977) conclude that the seafood waste chlorina-
tion methods used in Maryland were not effectively reducing coliform
counts to shellfish water standards. At the same time, residual chlorine
values were quite high (up to 89 mg/1 for six blue-crab processing
facilities). Options for improving this condition include either
improved chlorination-dechlorination or use of an alternative disinfec-
6-3*
-------
FIGURE 6.2-1
TYPICAL STEPS INVOLVED IN PREPARING
SEAFOOD FOR MARKET
SEAFOOD FROM
FISHING BOATS
i
co
PACKING
HOUSE
• HEADING FOR SHRIMP
AND FOR FISH (If not
done aboard fishing boats)
• WASHING
• SORTING
• PACKING ON ICE
WHOLESALE
OR RETAIL
OUTLETS
SEAFOOD
PROCESSING
PLANTS
•THAWING
• PEELING
• SORTING
• CLEANING
•MEAL PROCESSING
• BREADING
-------
tant (e.g., ozone or UV radiation). Adequate disinfection may be more
necessary for discharges to saltwater wetlands than for discharges to
freshwater wetlands, 1f shellfish-harvesting waters exist adjacent to the
saltwater wetlands.
Wastewaters are generated from many different seafood processing
activities. As an example, the types of wastewater generated during
shrimp processing are shown in Figure 6.2-2. Some of these steps can be
done aboard a shrimp boat, depending upon the intensity of shrimp har-
vesting and the type of boat.
The following discussion for shrimp processing does not necessarily
apply to other types of seafood. However, the variations 1n wastewater
quantities shown for shrimp may be typical of other seafood operations.
Table 6.2-1 lists basic processing steps for other types of seafood.
Two types of shrimp handling facilities are utilized; packing
houses and processing plants. Shrimp are often de-headed at sea, except
during peak harvesting periods when at least part of the catch is de-
headed at the packing houses. A typical shrimp packing house handles
1,000 to 1,500 pounds of shrimp per day. Discharges of wastewater can
range from 1,500 to 9,000 gallons per day (Gates et al., 1982). Shrimp
processing plants, on the other hand, handle 10,000 to 30,000 pounds of
shrimp daily and generate 100,000 to 300,000 gallons of effluent per day
(approximately 10 gallons per pound of shrimp processed; Gates et al.,
1982).
6-38
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FIGURE 6.2-2
TYPICAL SHRIMP PROCESSING SCHEMATIC
1
SOLID
T(
LANDI
WASTE
DEBRIS I orrciVTwr
V
« UFHRI5 [ INSPECTION
[ WEIGHING
WASTE " 1
3 i *
'ILL I PEELING
A
CLEANING
4
| SEPARATING
FLOW I
y .- •
1 GRADING
PRODUCT FLOV^ 4
TO
I DEVEINING
*
. PEPRIS 1 INSPECTION
1 , *
1 ANDFT1 L 1 BLANCHING. „
*
[ COOLING
4
1 KDflnTMR
.1
. PEBRIS — [FINAL INSP.
1 , *-
rn i ANnFTl 1 1 CANNING
1 RFSORTING
r-*
1 COOLING
*
1 PAC^IfiP
-| OFBRI5. WATER ^
f
D
-i HEADS. SHELLS
D — f
U
. WATER ^
-I SHELL MATERIAL, WATER
J
— 1 WATER
p
— 1 SHRIKPMEAT. VFTNS. WATFR
u
— 1 SHRIMPKEAT BRINE WATER
[
u
n
. HATER u
— 1 SALT WATER
J
_J '
^)
Source: Otwell(ed.), 1981
NON-COriTACT HASTEWATER
WATER TO
SCREENING AREA
6-39
-------
TABLE 6.2-1
CHARACTERISTICS OF VARIOUS TYPES
OF SEAFOOD PROCESSING
Type of
Seafood
Blue Crab
Shrimp
Finfish
Oysters
Processing Step Wastes From Process
Receiving
Steam cooking
Cooling
Meat picking
Packaging
Water
Cooking condensate
Water
Shells, legs
See Figure 6.2-2 See Figure 6.2-2
Receiving
Washing,
separating,
icing
Sorting
Grading
Re-icing
Water, fish wastes
Water, scales
Blow tanks are
much of waste-
water
Comments
Water usage is small
throughout blue crab
processing plants,
except for plants
with claw picking
machines. Effluent
from claw picking
machine operations
are not as biode-
gradable as effluent
from other crab
processing plants.
Portions of catches
in the southeastern
U.S. are often
de-headed at sea.
Wash water from
rollers can be fresh
water or salt water.
For three plants
surveyed in North
Carolina, average
wastewater quantities
were 1.3 gallons per
pound of raw fish
processed. Five-day
BOD of the untreated
effluent at the same
three plants averaged
190 mg/1.
For three plants
surveyed in North
Carolina, average
wastewater quantities
were 3.0 gallons per
pound of oyster meat.
Five-day BOD of the
untreated effluent at
the same three plants
averaged 400 mg/1.
6-40
-------
TABLE 6.2-1
CHARACTERISTICS OF VARIOUS TYPES
OF SEAFOOD PROCESSING
(Continued)
Type of
Seafood
Scallops
Processing Step
Receiving
Shocking
Evisceration
Wastes From Process
Most wastes are
generated during
evisceration
Comments
For twelve plants in
North Carolina, un-
treated effluent
volumes ranged from ]
to 15 gallons per
pound of scallop
meat. Five-day BOD
concentrations in
untreated effluent
ranged from 700 to
2,700 mg/1.
Information sources: U.S. EPA, 1974 and Otwell, 1980.
6-41
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The following characteristics correspond to screened wastewater from
a plant that peels, sorts, thaws and cleans seafood which was sampled
during a randomly selected day of operation (Gates et al. in Otwel1,
1981):
Biochemical oxygen demand (BOD) mg/1 280
Suspended solids, mg/1 90
Ammonia nitrogen, mg/1 2.2
Total coliforms, per 100 ml 94,000
Fecal coliforms, per 100 ml 6,700
mg/1 - milligrams per liter
ml - milliliters
Table 6.2-2 provides wastewater quality information for a large com-
bined seafood operation following wastewater treatment. Variations in
processing plant effluent are due to variations in activities that, by
coincidence, were noted in samples taken during different tidal periods.
Information in Table 6.2-2 indicates that effluent concentrations
from seafood-processing plants can vary considerably depending primarily
upon the quality of wastewater being treated. In addition, treated
wastewater characteristics shown in Table 6.2-2 are of lower quality than
the receiving waters. Ammonia-nitrogen values were significantly higher
in the effluent than in the receiving waters. Fecal coliform counts for
the processing plant effluent exceeded the Georgia guidelines for waters
used for recreation, fishing, shellfish, game, fish propogation and other
aquatic life, but were within guidelines of 5,000 fecal coliforms per 100
ml designated for agricultural and navigational waters. Dissolved oxygen
levels were below the Georgia Environmental Protection Division minimum
of 4.0 mg/1. However, because values below 3.0 mg/1 were also measured
6-42
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TABLE 6.2-2
ANALYSIS OF SELECTED PACKING HOUSE AND PROCESSING PLANT
EFFLUENTS IN THE VICINITY OF BRUNSWICK, GA
DURING JULY-AUGUST 1979
Station
Packing House
Effluent (1
sample)
Processing
Plant
Effluent
a. During a
July 1979
low tide
b. During a
July 1979
high tide
i c. During an
£ Aug. 1979
low tide
d. During an
Aug. 1979
high tide
Footnotes:
General Notes:
Biochemical , Suspended
Oxygen Demand, Solids
pH mg/1 mg/1
7.9 420 13
7.6 300 120
7.6 260 60
8.5 280 98
7.7 270 80
Turbidity,
Forroazin Ammonia
Turbidity Nitrogen,
Units mg/1
5 0.2
30 2.0
24 1.6
2.4
32 2.6
1. Biochemical oxygen demand values are probably five-day BOD values.
sampling and BOD analyses.
2. MPN is defined as most probable number of organisms.
1. Reference: Gates et al., 1982
Total Fecal
Salinity. Dissolved Coliforms, Coliforms
Parts per Oxygen, MPN* per MPN per
Thousand mg/1 100 ml 100 ml
2 4.3 150 43
0 7.6 24,000 2.400
7.5 2,400 1,100
3 5.6 240,000 11,000
0 7.6 110,000 2,400
The study report does not define the time between
2. Values presented are rounded from values presented in study report.
3. Effluent flows were 215,000 gallons per day from the processing plant. Packing house effluent resulted from heading of
approximately 1,000 pounds of rock shrimp.
-------
In undeveloped Georgia estuarine areas, the low dissolved oxygen levels
cannot be attributed exclusively to processing effluent. The biochemical
oxygen demand (BOD) load from this seafood-processing effluent was shown
to be equivalent to the organic materials generated by a 302-square meter
plot of salt marsh, and the ammonia-nitrogen levels were greater than,
but the same order of magnitude as, natural runoff from marsh land (Gates
et al., 1982).
Methods to reduce the amount of waste loads reaching treatment faci-
lities can be quite simple, such as collecting solids for solid waste
disposal. Manufacturing of secondary products from wastes generated
during primary processing is feasible for most if not all seafood types.
6.2.1.1 Seafood Uastewater Treatment
Various wastewater treatment options have been utilized to treat
seafood processing wastewaters:
Screening;
Dissolved air flotation (DAF) or other types of air flotation
treatment;
Other forms of physical-chemical treatment;
Biological treatment: activated sludge variations, trickling
filter(s), rotating biological contactor; and
Discharge to nearby municipal wastewater treatment plant.
Physical-chemical wastewater treatment is more appropriate for
seafood wastewaters than biological treatment, because physical-chemical
processes are more amenable to intermittent processing and also less
6-44
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space-intensive. However, physical-chemical processes are usually less
efficient when handling high BOD and suspended solids loadings.
Descriptions of the various physical-chemical treatment options are given
in Table 6.2-3. Screening and air flotation are utilized extensively by
food processing industries for wastewater treatment. Air flotation
treatment requires qualified, trained personnel preferably with a pre-
conceived operation and maintenance plan. General concerns or problems
associated with any treatment process used to treat seafood-processing
wastewaters are as follows: intermittent operation (e.g., 4 to 8 hours
per day for 120-150 days per year for shrimp processing along the Gulf
coast), long start-up and shut-down times each day, sludge with low
solids content, and variation of waste concentrations entering the treat-
ment process(es).
Wastewater treatment requirements are based on Best Conventional
Pollutant Control Technology (BCT) for control of BOD, total suspended
solids, fecal coliforms, pH, oil and grease. BCT replaced Best Available
Treatment Economically Achievable (BAT). The BCT guidelines (Table
6.2-4) are resulting in concern within the seafood processing industry
regarding wastewater treatment costs. BCT regulations have not been
promulgated; proposed draft regulations are due to be published for
public review by early 1984 (U.S. EPA, personal communication, September
1983). Brinsfield and Phillips (1977) conclude that static screens can
meet limitations (as of 1978) for clam processors and shrimp processors
in Maryland. Screens are not sufficient to meet limitations (as of 1978)
for blue crab and fish processors in Maryland.
6-45
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TABLE 6.2-3
DESCRIPTIONS OF PHYSICAL-CHEMICAL TREATMENT
PROCESSES UTILIZED TO TREAT SEAFOOD PROCESSING WASTEWATERS
Treatment Process Description of Process
Screening Solid and soluble constituents are separated from
wastewater by a mesh of fibers as the wastewater
flows perpendicular to the mesh. Many different
types of screens can be utilized.
Sedimentation Solid-liquid separation is accomplished by
allowing solids to settle from liquid. Addition
of chemicals can enhance removal of solids and
soluble constituents.
Air flotation Buoyant air lifts wastewater constituents to the
(vacuum, dispersed water surface. Surface sludges are then skimmed,
or dissolved) collected and dewatered. Chemicals can be added
to enhance treatment efficiency. Flow can also
be recycled to avoid process interruptions.
Chemical oxidation Chlorine and ozone can oxidize organic matter
thereby removing BOD and chemically converting
other compounds. High chemical costs restrict
use of this treatment process.
6-46
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TABLE 6.2-4
TECHNOLOGY ASSESSMENT FOR THE
SEAFOOD PROCESSING INDUSTRY IN THE CONTIGUOUS U.S.
Segment
BAT
BCT
BCT
Rationale
Catfish
Mechanized Blue
Crab
Shrimp
Tuna
Mechanized
Salmon
Mechanized
Bottom Fish
Mechanized Clam
Steamed/Canned
Oyster
Sardine
Herring Fillet
Aerated Lagoon
Aerated Lagoon
DAF
Roughing Filter
and Activated
Sludge
DAF
DAF
Aerated Lagoon
Aerated Lagoon
DAF**
DAF
Aerated Lagoon
DAF
DAF
DAF
DAF
DAF
Grit Removal
and DAF
Grit Removal
and DAF
DAF*
DAF
Same as BAT
Technology Transfer
from West Coast
Crab*
Data from Full-scale
Facilities
Data from Full-scale
Facilities
Data from Full-scale
Facilities
Technology Transfer
from Tuna
Technology Transfer
from S/C Oyster
Data from Full-Scale
Facilities
Data from Full-Scale
Facilities
Technology Transfer
from Mechanized
Salmon
* Performance data was collected during a pilot-scale study.
** Treatment of fresh water stream only.
NOTE: Both BAT and BCT include in-plant measures.
DAF - Dissolved Air Flotation
Source: Ertz in Otwell (ed.), 1981
6-47
-------
The costs for treating seafood processing wastewaters vary with the
volume of seafood processed, type of treatment and method of operation.
6.2.1.2 Other Planning Considerations
Wastewater disposal options are the same for seafood processors as
they are for municipal dischargers. However, wide variations in
discharge characteristics that can occur at a seafood processing plant
over time must be considered. Decisions about the suitability of seafood
wastewaters entering wetlands need to be based on the type of information
presented in both Sections 6.1 and 6.2 of this report. The function and
use of the wetland that may receive the wastewater should be considered
as part of the processing of assessing the suitability of any wastewater
discharge.
Changes in water conservation, by-product conservation, seafood pro-
cessing, or wastewater treatment techniques at processing plants can
alter the effect of treated wastewater on the receiving environment.
Improved by-product conservation, in particular, would reduce waste con-
centrations in wastewater effluent. The agency responsible for main-
taining the receiving environment should be aware of any changes at a
seafood processing plant in order to better assess environmental impacts.
6.2.2 Design and Installation
Selections of sizes for treatment facilities should be based on
costs, waste flow rates and variations, waste quality characteristics,
projections of seafood processing expansions, and effects of treated
6-48
-------
wastes on the receiving environment. Capacity for storage prior to
treatment could also be provided in order to reduce fluctuations of quan-
tities of wastewater entering the treatment facility.
Selection of treatment processes should be based on pilot-scale,
laboratory test results showing the treatability of the wastewater with
various types of processes. Each of the potential wastewater treatment
processes have different design considerations as outlined in Table
6.2-5. Many design values area variable depending upon results of bench-
scale laboratory studies of wastewater treatability or depending upon
wastewater volumes and characteristics. Treatment of seafood-processing
wastewaters has not been studied to the extent that treatment of munici-
pal wastewaters has been studied.
The need for chlorination or some other form of disinfection is one
type of decision for the seafood processor and the regulatory agency to
make. Chlorination can result in various efficiencies of killing patho-
genic microrganisms depending upon the degree of wastewater treatment
prior to chlorination, the pH and salinity of the wastewater and other
factors.
Design and installation of wastewater storage and disposal facili-
ties should follow the same guidelines outlined in Section 6.1.2. All of
the considerations associated with costs, environmental impacts, opera-
tion and implementation of storage and disposal facilities presented in
Section 6.1.2 apply to seafood-processing wastewaters as well.
6-49
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TABLE 6.2-5
DESIGN PARAMETERS FOR TYPES OF SEAFOOD
PROCESSING WASTEWATER TREATMENT
Type of Treatment
Screening
Design Parameter
Mesh size
Speed of rotating
or vibrating drum
(if applicable)
Angle of inclina-
tion (if applica-
ble)
Range of Design Parameter
Number
30 to 300
Variable
45 to 60
Chemical feed type
(if used)
Chemical feed rate
(if applicable)
Alum or iron
compound
Variable depend-
ing upon jar
test results
mesh
Units
1
degrees from
horizontal
Sedimentation
2
Overflow rate
Water depth
Detention time
Variable
Usually 6 to 10
30 to 120
—
feet
minutes
Chemical oxidation
(higher dosages of
oxidants than for
disinfection) or
disinfection
Selection of oxi-
dant
Method and costs
to obtain oxidant
Oxidant-wastewater
mixing time and
energy use
Size of oxidant-
wastewater contact
basin
Contact detention
time
Chlorine, ozone,
permanganate
Variable
Usually 1 to 5 Minutes
for mixing
Variable
Usually 30 to Minutes
60
6-50
-------
Type of Treatment
Air flotation
TABLE 6.2-5
DESIGN PARAMETERS FOR TYPES OF SEAFOOD
PROCESSING WASTEWATER TREATMENT
(Continued)
Design Parameter
Type of system
Pressure of waste-
water prior to
release to tank
(dissolved air flo-
tation only)
Type and quantities
of chemical addi-
tives (coagulants,
pH adjustment)
Size of flotation
tanks (water depth,
detention time)
Range of Design Parameter
NumberUnits
Vacuum, disper-
sed air or dis-
solved air
30 to 50
Pounds per
square inch
(psia)
Variable
Variable
Air diffusion rates Variable
Footnotes: Sieve openings for a 30-mesh sieve are approximately 600 microns
(approximately 0.024 inch). Sieve openings for a 300-mesh sieve
are approximately 50 microns (approximately 0.002 inch).
Overflow rate is defined as the volume of wastewater per day per
surface area of a sedimentation basin.
Data Sources: U.S. EPA, June 1974; Brinsfield and Phillips, 1977
and Otwell, 1981.
6-51
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6.2.3 Operation, Maintenance, Repair and Monitoring
Most of the operation, maintenance, repair and monitoring
considerations presented earlier in Sections 6.1.3 and 6.1.4 are also
applicable to seafood-processing wastewaters. Proper planning and design
can be nullified by improper operation, maintenance and repair. The lack
of information regarding the effects of seafood-processing wastewaters on
wetlands makes proper operation, maintenance, repair and monitoring par-
ticularly important. The cost savings associated with avoiding treatment
system overhauls by properly operating, maintaining and repairing a faci-
lity could be stressed to seafood processors. An effort by environmental
agencies may be needed to make seafood processors aware of the value of
operation, maintenance and repair activities.
Promotion of monitoring activities could be particularly difficult.
Seafood processors can contend that proper operation, maintenance and
repair is enough of an effort on their part to avoid adverse environmen-
tal impacts. The appropriate state environmental agency may need to be
responsible for monitoring activities with support from seafood pro-
cessors. Furthermore, the tendency for seafood-processing discharges to
be released periodically, rather than continuously, could further compli-
cate the assessment of monitoring results.
6.3 ENGINEERING-RELATED ISSUES AND OPTIONS
In summary, a number of issues remain unresolved in association with
the engineering of saltwater wetland wastewater systems. These issues
include flow and chemical transport complexities of saltwater wetlands as
6-52
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well as considerations that vary with different saltwater wetland areas.
Table 6.3-1 lists a number of important issues that need to be resolved
with additional research and/or judgments and options. Engineering
options can be developed to address many Issues. By preparing an inven-
tory of all options and determining how well they address the issues, the
reasonableness of allowing discharges to saltwater wetlands can be esti-
mated.
6-53
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TABLE 6.3-1
ENGINEERING-RELATED ISSUES AND
OPTIONS FOR SALTWATER WETLANDS
ISSUES
Determining appropriate wetland hydraulic, organic, and
nutrient loading rates;
Estimating wastewater detention time within wetlands;
Estimating levels of metal and organic compounds in soils
and vegetation
-------
TABLE 6.3-1
(Continued)
ENGINEERING-RELATED ISSUES AND
OPTIONS FOR SALTWATER WETLANDS
SOME OPTIONS (continued)
Multi-port or gate distribution of wastewater;
Containment dikes, berms, weirs to separate wetland into
plots;
Mosquito control (as needed);
9
Plant harvesting and by-product production;
Introduction and promotion of free-floating aquatic plants
- sale and transport of plants are limited legally,
- free-floating vegetation can not survive in tidal areas
which are not continuously covered with water,
- many types may not be able to tolerate saltwater
conditions.
Spraying of wastewater;
Planned resting periods when no wastewater would be
discharged;
Dechlorination: pond capacity or use of sulfur dioxide
following chlorination; and
Use of a back-up or alternate discharge mechanism.
6-55
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6.4 LITERATURE CITED
American Public Health Association (APHA) et al., 1975. Standard Methods
for the Examination of Water and Wastewater. Fourteenth edition.
Brinsfield, R.B. and D.G. Phillips. August 1977. Waste Treatment and
Disposal from Seafood Processing Plants. EPA-600/2-77-157. Ada,
OK, August 1977.
Brown and Caldwell, September 1982. Preliminary Design and Marine Survey
for Ocean Outfall: Dare County, North Carolina. Prepared for Dare
County and the U.S. Environmental Protection Agency in association
with Law Engineering Testing Company.
Chan, E., T.A. Bursztynsky, N. Hantzsche and Y. Litwin, September 1982.
The Use of Wetlands for Water Pollution Control. EPA 600/2-82-086.
Cincinnati, OH.
Conner, W.H., J.H. Stone, L.M. Bahr, V.R. Bennett, J.W. Day, Jr., and
R.E. Turner. 1976. Oil and gas use characterization, impacts and
guidelines. National Oceanic and Atmospheric Administration
(NOAA-77021602). 148pp.
Edzward, J.K., J.B. Upchurch and C.R. O'Melia, October 1972. Coagulation
in Estuaries. Presented at the 45th Annual Conference of the
Water Pollution Control Federation, Atlanta, GA.
Gates, K.W., B.E. Perkins, J.G. EuDaly, A.S. Harrison and W.A. Bough,
1982. Assessment of Seafood Processing and Packing Plant
Discharges and their Impacts on Georgia's Estuaries. Georgia
Marine Science Center. Skidaway Island, GA. Technical Report
Series Number 82-3.
Hammer, D.E. and R.H. Kadlec, April 1983. Design Principles for Wetland
Treatment Systems. EPA 600/2-83-026. Ada, OK.
Hyde, H.C. and R.S. Ross, 1980. Technology Assessment of Wetland for
Municipal Wastewater Treatment. EPA 68-03-3016. U.S. EPA,
Cincinnati, OH.
Klapow, L.A. and R.H. Lewis, 1979. Analysis of Toxicity Data for
California Marine Water Quality Standards. Journal of the Water
Pollution Control Federation, Vol. 51, No. 8.
Meo, M., J.W. Day, Jr., and T.B. Ford, November 1975. Overland Flow in
the Louisiana Coastal Zone of the Sea Grant Development Center for
Wetland Resources, L.S.U., Baton Rouge, LA.
Nelson, R.W. and E.G. Weller. 1984. A better rationale for wetland
management. Environmental Management, Vol. 8, No. 4.
Springer-Verlag, New York, Inc., New York. pp. 295-308.
6-56
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LITERATURE CITED (continued)
Otwell, W.S., February 1981. Seafood Waste Management in the 1980's:
Conference proceedings, September 23-25, 1980. Report Number 40,
Florida Sea Grant College.
Reeco, Renee, U.S. EPA, personal communication, Washington, DC.
September 1983.
Robert Snow Means Company, Inc., 1983. Means Construction Cost Data,
Kingston, MA.
Stewart, R.K. and D.R. Tangarone, 1977. Water Quality Investigation
Related to Seafood Processing Wastewater Discharges at Dutch
Harbor, Alaska, October 1975 - October 1976. U.S. EPA, Seattle,
WA. EPA 910/8-77-100.
Stowell, R., R. Ludwig, J. Colt and G. Tchobanoglous, August 1980.
Toward the Rational Design of Aquatic Treatment Systems, ASCE
Spring Convention, Portland, OR. April 14-18, 1980.
Tarquin, A.J., June 1976. Treatment of High Strength Meatpacking Plant
Wastewater by Land Application, EPA-600/2-76-302. U.S. EPA, Ada,
OK.
U.S. EPA, June 1971. CRESA and Engineering-Science of Alaska - Pollution
Abatement and By-Product Recovery in Shellfish and Fisheries
Processing. U.S. EPA 11060FJQ.
U.S. EPA, June 1974. Development Document for Effluent Limitations
Guidelines and New Source Performance Standards for the Catfish,
Crab, Shrimp, and Tuna Segment of the Canned and Preserved Seafood
Processing Point Source Category. 440/1-74-020-a.
U.S. EPA, May 1975. Finger-fill Canal Studies: Florida and North
Carolina EPA-940/9-76-017.
U.S. EPA, July 1976. Quality Criteria for Water. Office of Water and
Hazardous Materials, Washington, DC.
U.S. EPA, September 1979. Aquaculture Systems for Wastewater Treatment:
Seminar Proceedings and Engineering Assessment. EPA 430/9-80-006.
Washington, DC, September 1979.
U.S. EPA, February 1980. Innovative and Alternative Technology
Assessment Manual. Office of Water Program Operations.
Washington, D.C. MCD-53; EPA 430/9-78-009.
U.S. EPA, February 1983. Freshwater Wetlands for Wastewater Management
EIS, Phase I Report. U.S. EPA, Atlanta, GA.
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7.0 SUMMARY OF INSTITUTIONAL. SCIENTIFIC AND
ENGINEERING CONSIDERATIONS
The key institutional, scientific and engineering
considerations that affect the use of saltwater
wetlands for wastewater management are summarized.
Additionally, areas that require further study are
identified.
7.1 INSTITUTIONAL CONSIDERATIONS
Institutional control of wastewater management in saltwater wetlands
is carried out at both the federal and state level. Federal involvement
is through both funding and regulatory programs. The scope of involve-
ment varies among these programs from a limited advisory role to full-
scale review and issuance of discharge permits. The scope of control
also varies widely at the state level.
7.1.1 Federal Involvement
Federal involvement with wetland discharges takes place primarily
through four programs, the Water Quality Standards Program, the National
Pollutant Discharge Elimination System (NPDES) Permit Program, the 201
Construction Grants Program and the Section 404 Dredge and Fill Permit
Program, all promulgated under authority of the Clean Water Act.
The water quality standards program provides for a mechanism which
defines the water quality goals of a water body and by which criteria are
established to protect or achieve those uses. Standards are adopted to
protect public health or welfare, enhance the quality of water and serve
the purposes of the Clean Water Act. Water quality standards should,
wherever attainable, provide for the protection and propagation of fish,
shellfish and wildlife and provide for recreation in and on the water.
7-1
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The NPDES program is a process for permitting point source
discharges into waters of the United States including saltwater wetlands.
All states within the project area except Florida have been delegated
responsibility for the NPDES program by the United States Environmental
Protection Agency (USEPA).
The 201 Construction Grants Program is the vehicle for providing
federal funding for the development of municipal wastewater facilities.
The 201 Program only pertains to saltwater discharges if a municipality
wishes to receive a federal grant to assist with developing a facility
that would treat and discharge municipal wastewaters to saltwater
wetlands. Such projects may be eligible for funding under the 201
Program. The possibility of receiving federal funds could result in a
more detailed evaluation of environmental impacts. Each of the study
area states implements the 201 Program under USEPA authority. The manner
in which funds are available varies from state to state.
The Section 404 Dredge-and-Fill Permit Program administered by the
Army Corps of Engineers (COE) is another federal regulatory program
affecting wetland discharges. A Section 404 permit may be required 1f
dredging and filling will take place as a result of construction of
wastewater facilities in wetland areas.
The USEPA shares a responsibility with the COE under Section 404
with respect to any dredge and fill activity, including operations 1n
wetlands. Additionally, the Department of the Interior, Fish and
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Wildlife Service (FWS), and the Department of Commerce, National Marine
Fisheries Service (NMFS) share permit application review responsibilities
in terms of potential environmental impact on the resources of saltwater
wetlands. The roles of both these agencies are purely advisory.
7.1.2 State Involvement
Each state has the authority to regulate activity in their respec-
tive coastal zones. The means of regulation include enforcement of water
quality criteria, issuance of discharge permits (with the exception of
Florida) and project prioritization for construction grant funding. A
lack of consistency exists among the states in several areas which
influences the effectiveness of wetland permitting along the entire
coastal zone. A number of key issues result from the manner in which the
states carry out these programs.
7.1.2.1 Water Quality Standards
The key issue concerning water quality standards is whether a state
has a specific classification for saltwater wetlands and whether numeri-
cal criteria have been established that recognize the natural water
quality characteristics of wetlands. Not all the states within USEPA
Region IV have established specific classifications for saltwater areas.
All of these states, however, do recognize a separate classification for
shellfishing waters. The USEPA Region IV states, except Georgia and
Mississippi, have allowances for lower background levels for dissolved
oxygen in wetland waters. Exceptions are also made for other parameters
in some states. However, except where such allowances are made for
7-3
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wetlands, the criteria applied are likely to be the same as for adjacent
open waters. This may result in stringent criteria for wetlands and
discourage the use of wetlands for discharges. An alternative would be
to develop site-specific criteria. Some of the states have experimented
with this approach.
7.1.2.2 NPDES Permits
The main issue regarding saltwater discharges is how effluent limits
are set for wastewater discharge permits. Based on the requirements of
the Clean Water Act, any discharge to saltwater wetlands would need to
receive a minimum of secondary treatment. Where the receiving body is
defined as water quality limited, more stringent standards would need to
be met. One of the problems is that in many cases there has been no
determination as to whether a particular wetland is effluent limited or
water quality limited. It is likely that the finding for the adjacent
water body would be applied. If the decision is that the wetland is
water quality limited, the problem of how to determine an effluent limi-
tation is raised. Wetland effluent limitations are difficult to simulate
mathematically due to their unique hydrological and biological charac-
teristics.
The states' responses to this situation have varied. Some prescribe
only secondary treatment in all wetland areas. Some use conventional
water quality models, others use modified models, still others use
experience from past permit reviews.
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7.1.2.3 Construction Grants Program
The primary issues under the 201 Construction Grants Program concern
eligibility, funding levels and project prioritization. All of the
states within USEPA Region IV indicate that they would consider a project
which incorporates a wetland discharge to be grant eligible. Components
of the project that are eligible are, however, unclear. The approach to
funding levels varies, however. USEPA Region IV states do not give a
specific preference to wetland discharge projects, but most consider such
projects to be either "alternative" or "innovative" and thereby eligible
for separate funds set aside for these types of projects. A few of the
states including Georgia and Florida give some preference to "innovative"
or "alternative" technology projects in setting funding priorities. In
South Carolina one of the ranking factors would be rated higher for
wetland projects.
7.1.2.4 Other Programs
There are other programs that are not specifically focused on water
quality which could impact saltwater discharge projects. Each of the six
states administers some form of coastal area management program. In
Mississippi, Alabama, Georgia and South Carolina a coastal permit would
be required for a wetland discharge. North Carolina specifically prohib-
its certain activities (which may include the use of wastewater facili-
ties) from some coastal areas. In Florida, construction within the
coastal zone would require additional state permits.
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7.2 SCIENTIFIC CONSIDERATIONS
Components of saltwater wetland ecosystems include geomorphology,
vegetation, hydrology, water quality and wildlife. Biotic and abiotic
factors operate in dynamic equilibrium and the characteristics, functions
and processes of saltwater wetlands are variable and interrelated. The
discharge of municipal or seafood-processing wastewater has the potential
of disrupting the integrity of these wetlands. However, the potential
for positive effects must also be considered.
Five major factors were identified as being important when eva-
luating a potential saltwater wetlands discharge:
Erosion would be expected to vary with characteristics of the
soil, density of vegetation and effluent rates per unit of marsh
surface area.
Nutrients may affect the marsh vegetation and/or the estuary.
The types or amounts of nutrients entering the marsh would
depend on the characteristics of the effluent, while their path-
ways in the marsh would depend on such factors as sediment
characteristics, uptake rates by vegetation and frequency of
tidal inundation.
Toxic substances and pathogens entering the marsh will also vary
with the quality of the effluent. This factor is particularly
relevant for consideration because of public health implica-
tions.
Vegetation may be affected by several parameters associated with
wastewater disposal including decreased salinity, continual soil
saturation and nutrient loading. A primary concern is that
shifts in plant species composition or distribution may occur in
the marsh.
Wildlife may be affected if shifts in the vegetation occur that
alter food availability, nesting sites, cover or similar habitat
parameters. Wildlife could also be affected by toxic substances
introduced with treated effluent. The occurrence of
threatened and endangered animal species is another reason for
wildlife to be a factor for consideration.
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7.3 ENGINEERING CONSIDERATIONS
Numerous factors are important to consider as a wetland-wastewater
system is being planned, designed, installed, operated, maintained and
monitored (Tables 7.3-1 and 7.3-2). Planning factors are more numerous
than the other types of factors because planning, by definition, encom-
passes all subsequent engineering activities.
To date, observed practices seem to indicate that wastewater treat-
ment plant (WWTP) discharges are usually located at the edge of a wetland
area. Little or no monitoring of the effluent occurs once it enters the
wetland. As a result, the wetland which receives wastewater is seldom
evaluated during any engineering stage: planning, design, installation,
operation, maintenance-repair or monitoring. This hands-off philosophy
also holds down the financial burden of WWTP operations, which is an
important objective for both municipal managers and seafood-processing
industries. Moreover, existing complexities regarding wetland hydrology
and wetland physical-chemical-biological processes cannot be addressed
without relatively extensive monitoring and wetland maintenance efforts.
7.4 KEY FACTORS
Key scientific and engineering factors for evaluating saltwater
wetlands as potential wastewater discharge sites are geology, hydrology
and water quality. The key institutional factor is regulatory control.
Geological components refer to composition of the sediments,
particularly as they relate to porosity (permeability) and move-
ment of water or wastewater into or through the sediments.
Hydro-logical components refer to the discharge volume and
rate(s) of application, as well as to tidal fluctuations,
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TABLE 7.3-1
ENGINEERING FACTORS PERTINENT TO UTILIZING WETLANDS
FOR ANY TYPE OF WASTEWATER MANAGEMENT
Factor
ilonl.
Design Installation Operation Maintenance Monitoring
Comments
I
oo
Level of treatment prior to
discharge to wetland
and from wetland
Evaluation of other waste-
water disposal options
besides use of wetlands
Evaluation of various wetland
disposal sites
Other use(s) of wetland
besides wastewater manage-
ment
Estimating best time of year
for Installation activities
within a wetland (if any)
Impacts of wastewater on life
forms, soils and ground-
water
Advantages and disadvantages
of chlorine usage, other
forns of disinfection and
dechlorination
Wastewater loading rates
(hydraulic, organic and
nutrient loadings), de-
tention tine and flow
paths
Treatment rates for various
wetlands on a seasonal
basis
Method for applying waste-
water to a wetland
Financial burden in compari-
son to environmental im-
pacts, operation and
implementation
Providing and effectively
utilizing wastewater
storage to enhance the
wetland
Techniques for enhancing
wetland use through
wetland maintenance
Minimum requirement is secondary treatment
prior to discharge to wetland
At many locations, no other reasonable alter-
native may exist
Usually wastewater is discharged adjacent to
the wastewater treatment plant
Assessing effects of numerous wetland usages
is usually the responsibility of regulatory
agencies
Seldom evaluated by dischargers
Seldom evaluated by dischargers
Seldom evaluated by dischargers
Not well understood but believed to be
variable
Usually a single pipe discharge at the edge of
a wetland is utilized. Energy costs and pipe-
line placement are primary considerations
Financial burden is usually minimized
Seldom evaluated by dischargers
Seldom evaluated by dischargers
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TABLE 7.3-1
(continued)
ENGINEERING FACTORS PERTINENT TO UTILIZING WETLANDS
FOR ANY TYPE OF UASTEWATER MANAGEMENT
Factor
(or consideration)
Planning Design Installation Operation Maintenance Monitoring
Comments
Use of back-up wastewater
disposal systems (e.g.,
other wetland areas or
perhaps land applica-
tion at upland areas)
Mininizing wetland distur-
bances with installation,
operation and mainte-
nance of wetland-waste-
water system
Reliability for long-term
wastewater management
Extent to which ecosystem
can be modified without
adversely affecting
other wetland uses
Artificial creation of
wastewater management
Effects of industrial waste-
water managed separately
or blended with munici-
pal wastewaters
Need for a pi lot-scale
facility
Contingency planning to
address extreme weather,
spills or treatment
failures
Seldom evaluated by dischargers; options are
limited by distance to alternative discharge
location and associated costs
Not well understood, particularly for salt-
water wetlands
Not well understood, particularly for salt-
water wetlands
Seldom, if at all, considered in detail for
saltwater wetland; regulation of tidal effects
would be particularly difficult
Effects vary depending upon type, flow and
quality of the industrial waste and the type
and size of the wetland area receiving the
wastewaters
Added costs are a disadvantage while advan-
tages are often not tangible
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TABLE 7.3-2
ENGINEERING FACTORS PERTINENT TO UTILIZING WETLANDS
FOR SEAFOOD-PROCESSING WASTEWA1ER MANAGEMENT
I
t—'
o
Factor
(or consideration)
Planning Design Installation Operation Maintenance Monitoring
Comments
Extreme variability of
wastewater flows and
qualities at one
location
Compatibility of waste-
water and wetland; need
for a pilot-scale study
Selection of treatment
processes and required
effluent quality
Effects of changes in in-
dustrial activities on
utilization of wetland
for wastewater manage-
ment
Those responsible for wetland maintenance and
monitoring, should keep in communication with
seafood products superintendents
The need for a pilot-scale study is considered
to be greater for seafood processing wastewa-
ters than for municipal wastewaters which have
no significant industrial components.
Regulatory agency involvement is needed that
is consistent for each discharger in a par-
ticular state
Seldom evaluated by discharger
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water-table level, seasonal precipitation, runoff and other
natural factors.
Water quality components refer to the constituency of the
effluent and to potential changes in water quality parameters
following discharge.
Regulatory control refers to permitting, enforcement of water
quality standards and funding. Regulatory requirements may pro-
mote or restrict the use of saltwater wetlands for wastewater
discharge.
These key factors could affect the vegetation or wildlife within the
marsh, public health, or use of the marsh as an alternative for
wastewater management.
7.5 STUDY RECOMMENDATIONS
The use of saltwater wetlands for the management of municipal or
seafood processing wastewater is an area in which many technical
questions remain unanswered. The focus of much of the recent wetland
wastewater systems research has been directed more toward freshwater
rather than saltwater systems. In recognizing the requirements of salt-
water wetlands and the differences between saltwater and freshwater
systems, several technical areas have been identified in this report that
are appropriate for further study. Areas for further study are grouped
into soils/geomorphology, vegetation, hydrology, water quality, wildlife
and engineering topics.
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7.5.1 Soi1s/Geomorphology
Wetland surface area needed to meet wastewater management
objectives;
Wastewater loading rates based on uptake of nutrients by soils;
Relating estuarine characteristics (river and tidal flows,
depositional/erosional patterns, sediment budgets, tidal energy,
soil characteristics, etc.) to wastewater discharges;
How metals, toxics and pathogens are tied up or released from
sediments;
How long pathogens remain viable in sediments.
7.5.2 Vegetation
Nutrient removal abilities of saltwater wetland vegetation;
Effects of freshwater wastewater discharge on saltwater wetland
vegetation;
Wastewater discharges to mangrove systems;
Effects of toxics, metals and pathogens on vegetation.
7.5.3 Hydrology
Seasonal hydrological parameters that might affect nutrient
flushing;
Groundwater flow patterns;
Hydraulic loading and loading rates;
Relating hydraulic loading in terms of frequency, duration, and
water depth to effects on vegetation and animal life, soil
saturation, decreased storage capacity, etc.;
Discharge velocities to avoid erosion;
Effects of discharges on seasonal wet/dry cycles;
Effects of continual innundation on oxygen levels in marsh
waters and the resultant effects on nutrient availability.
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7.5.4 Water Quality
Long-term ability of saltwater wetlands to assimilate wastewater
and the long term effects of wastewater loading on saltwater
wetlands;
The effects of seasonal influences, tidal influences and coastal
storms and tidal surges on wetland water quality in wetland
wastewater systems;
Loading rates needed to maintain water quality.
7.5.5 Wildlife
Impacts on wildlife from wastewater application;
Impacts on wildlife from freshwater wastewater influences;
Relating changes in vegetation to effects on wildlife;
Impacts on wildlife (including shellfish) related to toxic
substances, metals, pathogens;
Food chain effects related to wastewater discharges (Including
effects of metals, toxins and pathogens).
7.5.6 Engineering
Design criteria for hydraulic nutrient and organic loading rates
to saltwater wetlands;
Effects of seafood processing wastewater on saltwater wetlands;
Criteria for establishing detention times or water depths;
Effects of chlorine or other disinfectants in terms of public
health and ecosystem toxicity;
Distribution systems and schedules;
Need for back-up systems and storage capacity;
. Downstream monitoring.
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8.0 LIST OF PREPARERS
U.S ENVIRONMENTAL PROTECTION AGENCY
Robert B. Howard Chief, NEPA Compliance Section
Ronald J. Mikulak Project Officer
APPLIED BIOLOGY, INC.
PRIME CONTRACTOR
Nancy W. Walls Project Manager
Sue A. McCuskey Project Director
David 0. Herrema Environmental Scientist
William B. Rhodes Ecologist
Kenneth J. Stockwell Ecologist
Christopher Hoberg Ecologist
Stephen C. Wiedl Ecologist
Alyse Gardner Ecologist
Joan Dupont Ecologist
GANNETT FLEMING CORDDRY AND CARPENTER, INC.
SUBCONTRACTOR
Thomas M. Rachford Project Manager
David B. Babcock Environmental Engineer
Stuart Miner Institutional Analyst
Lynn Devel-Rezak Institutional Analyst
*U.S. GOVERNMENT PRINTING OFFICE! 9 8 "t -545 -067/
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