&EPA
United States
Environmental Protection
Agency
Draft Guidance for Aquatic Animal
Production Facilities to Assist in
Reducing the Discharge of Pollutants
-------
United States Environmental Protection Agency
Off ice of Water (4303T)
EPA-821-B-02-002
Washington, DC 20460
August 2002
-------
Draft Guidance for Aquatic Animal
Production Facilities to Assist in Reducing
the Discharge of Pollutants
Christine T. Whitman
Administrator
G. Tracy Mehan, III
Assistant Administrator, Office of Water
Geoffrey H. Grubbs
Director, Office of Science and Technology
Sheila E. Frace
Director, Engineering and Analysis Division
Marvin Rubin
Chief, Environmental Engineering Branch
Janet Goodwin
Technical Coordinator
Marta Jordan
Project Manager
Engineering and Analysis Division
Office of Science and Technology
U.S. Environmental Protection Agency
Washington, DC 20460
August 2002
-------
Acknowledgments and Disclaimer
This report has been reviewed and approved for publication by the Engineering
and Analysis Division, Office of Science and Technology. This report was
prepared with the support of Tetra Tech, Inc. under the direction and review of
the Office of Science and Technology.
Neither the United States government nor any of its employees, contractors,
subcontractors, or other employees makes any warranty, expressed or implied,
or assumes any legal liability or responsibility for any third party's use of, or the
results of such use of, any information, apparatus, product, or process discussed
in this report, or represents that its use by such a third party would not infringe
on privately owned rights.
-------
CONTENTS
SECTION 1: INTRODUCTION 1-1
1.1 Scope and Purpose of the Technical Guidance Manual 1-1
1.2 The Aquatic Animal Production Industry 1-1
1.3 Defining the Need for BMPs for the AAP Industry 1-3
1.4 Current Regulatory Structure: NPDES Program 1-4
1.5 State BMP Programs 1-4
1.6 Overview of Guidance Manual 1-7
1.7 References 1-8
SECTION 2: REQUIREMENTS CHECKLIST FOR CAAP FACILITIES 2-1
2.1 Introduction 2-1
2.2 Checklist 2-2
2.2.1 General Reporting Requirements 2-2
2.2.2 Flow-through System Requirements 2-3
2.2.3 Recirculating System Requirements 2-4
2.2.4 Net Pen System Requirements 2-4
2.3 References 2-5
Checklist for General Reporting Requirements, Part A 2-6
Checklist for General Reporting Requirements, Part B 2-7
Requirements for Flow-through Systems 2-8
Requirements for Recirculating Systems 2-19
Requirements for Net Pen Systems 2-22
Calculating Medicated Feed Content 2-23
SECTIONS: How TO WRITE A BMP PLAN 3-1
3.1 Introduction 3-1
3.2 Guidance for Developing a BMP Plan 3-1
-------
3.3 Guidance for Drug and Chemical Reporting Requirements 3-7
3.4 References 3-8
SECTION 4: BMPs FOR CAAP FACILITIES 4-1
4.1 Introduction 4-1
4.2 Feed Management 4-1
4.3 Designing and Maintaining Quiescent Zones 4-4
4.4 Designing and Maintaining Sedimentation Basins 4-7
4.5 Secondary Settling with Microscreens 4-9
4.6 Secondary Settling with Vegetated Ditches 4-10
4.7 Secondary Settling with Constructed Wetlands 4-11
4.8 Solids Disposal 4-13
4.8.1 Dewatering 4-13
4.8.2 Composting 4-13
4.8.3 Land Application 4-14
4.8.4 Publicly Owned Treatment Works 4-14
4.8.5 Storage Tanks and Lagoons 4-15
4.9 Active Feed Monitoring 4-15
4.10 Practices to Minimize the Potential Escape of Nonnative Species 4-16
4.11 Mortality Removal 4-16
4.12 Net Pen Siting 4-17
4.13 Net Cleaning 4-17
4.14 Discharge Management 4-18
4.15 Erosion Control 4-19
4.16 Managing Rainwater and Reducing Overflow 4-22
4.17 Using Drugs and Chemicals: Fertilizers, Therapeutic Agents,
and Water Quality Enhancers for Ponds 4-23
ii
-------
4.18 Oxidation Lagoons 4-24
4.19 References 4-24
APPENDIX A: ADDITIONAL RESOURCES A-l
APPENDIX B: SAMPLE BMP PLAN B-l
APPENDIX C: FACT SHEETS C-l
111
-------
-------
SECTION 1
INTRODUCTION
1.1 Scope and Purpose of the Technical Guidance Manual
The primary purpose of this document is to provide technical guidance for
concentrated aquatic animal production (CAPP) facilities to meet the
requirements of the proposed effluent limitations guidelines and standards. This
guidance manual can also be used by all aquatic animal production (AAP)
facilities to reduce discharges of pollutants. The manual describes a variety of
best management practices (BMPs) and other activities for use by AAP and
CAAP facilities to meet the goals of the effluent limitations guidelines. EPA has
found that many facilities are currently using BMPs described in this document
to successfully reduce pollution loadings.
The guidance manual presents BMPs that can be applied by all sectors of the
AAP industry and some BMPs that apply to specific sectors of the industry. This
guidance also presents several checklists for use by facilities for BMP plan
development and to assist with reporting requirements. The intended audience
for the technical guidance manual includes aquaculture facility owners and
managers, National Permit Discharge Elimination System (NPDES) permit
writers, and other local, state, and federal decision-makers.
1.2 The Aquatic Animal Production Industry
EPA is proposing new effluent limitations guidelines and standards for three
subcategories of the concentrated aquatic animal production industry including:
flow-through systems, recirculating systems, and net pens.
Flow-through systems consist of single- or multiple-pass units with constantly
flowing culture water, and they commonly use raceways or tanks (circular or
rectangular). Flow-through systems are found throughout the United States,
wherever a consistent volume of water is available. Most flow-through systems
use well, spring, or stream water as a source of production water. The water
source is chosen to provide a constant flow with relatively little variation in rate,
temperature, or quality. Flow-through systems are the primary method used to
grow salmonid species such as rainbow trout. These species require high-quality
cold water with high levels of dissolved oxygen. Flow-though systems are
located where water is abundant, which enables farmers to produce these types
of fish cost-effectively. Some other species cultured using flow-through systems
are hybrid striped bass, tilapia, and ornamentals.
1-1
-------
SECTION 1: INTRODUCTION
Recirculating systems are highly intensive culture systems that actively filter and
reuse water many times before it is discharged. These systems typically use tanks
or raceways to hold the growing animals and have extensive filtration and
support equipment to maintain adequate water quality. Recirculating systems
use biological filtration equipment to remove ammonia from the production
water. Solids removal, oxygenation, temperature control, pH management,
carbon dioxide control, and disinfection are other common water treatment
processes used in recirculating systems. The size of the recirculating system
depends primarily on available capital to fund the project and can be designed to
meet the production goals of the operator. Recirculating systems can be used to
grow a number of different species. They can be used anywhere in the country
because a relatively small volume of water is needed to produce a unit of
product.
Net pens and cages are suspended or floating holding systems in which some
cultured species are grown. These systems may be located along a shore or pier
or may be anchored and floating offshore. Net pens and cages rely on tides,
currents, and other natural water movement to provide a continual supply of
high-quality water to the cultured animals. In most locations, net pens are
designed to withstand the high-energy environments of open waters and are
anchored to keep them in place during extreme weather events. Strict siting
requirements typically restrict the number of units at a given site to ensure
sufficient flushing to distribute wastes and prevent degradation of the bottom
below and near the net pens.
EPA does not propose to establish effluent limitations guidelines for other types
of production systems, including floating aquaculture production systems (e.g.,
mussel rafts) or for ponds; however, this manual does address practices that
could be used for those systems to help reduce pollutant discharges.
EPA is not proposing regulations for discharges from the following:
• Ponds. The culture of aquatic animals in ponds requires high-quality water
to sustain and grow the aquatic animal crop. For many aquatic animals
raised in ponds, the pond itself serves as a natural biological treatment
system to reduce wastes generated by the animals in the pond.
• Lobster pounds. Intertidal "pounds" are used for live storage and feeding of
lobsters to keep wild caught animals alive pending sale.
• Crawfish. Crawfish are typically raised in seasonally filled shallow ponds
in conjunction with plant crops. After the plant crop is harvested,
remaining plant residues serve as a forage food for the crawfish.
1-2
-------
SECTION 1: INTRODUCTION
• Molluscan shellfish production in open waters. For large-scale production of
mollusks for food, operators typically use bottom culture, bottom-
anchored racks, or floating (but tethered to the bottom) rafts in open
waters. Molluscs do not require added feed because they remove nutrients
(in the form of algae) from ambient waters by filtration.
• Aquariums. Public aquariums are AAP facilities that display a variety of
aquatic animals to the public and conduct research on many different
threatened and endangered aquatic species. These systems maintain low
stocking densities and very clean, clear water to enhance the visual
display of the animals. Discharges from aquariums are likely to be low in
total suspended solids (TSS) and nutrients because of the low stocking
densities.
• Alligators. Alligator production facilities range in size from producers with
less than 100 animals to some with many thousands of animals. None of
the production facilities discharge effluents from their alligator
production systems. Instead, effluents are treated in one or two-stage
lagoons and then land applied to crop or forested land.
1.3 Defining the Need for BMPs for the CAAP Industry
The operation of CAAP facilities has the potential to introduce a variety of
pollutants and leads to other disturbances in receiving waters that might be
harmful to the environment. According to the 1998 U.S. Department of
Agriculture (USDA) Census of Aquaculture (USDA, 2000), there are
approximately 4,200 commercial aquaculture facilities in the United States.
Aquaculture has been among the fastest-growing sectors of agriculture until a
recent slowdown that began several years ago caused by declining or level
growth among producers of several major species.
Water quality concerns related to pollutant loads are only one of the
environmental concerns associated with this industry. Other areas of concern
relate to the introduction of invasive species from CAAP facilities, which can
pose serious potential and observed risks to native fishery resources and wild
native aquatic species from the establishment of escaped individuals (Carlton,
2001; Volpe et al., 2000). Some CAAP facilities may also use drugs, such as
oxytetracycline or formalin, and chemicals, such as a variety of copper-
containing pesticides, that may be released into receiving waters. For some
applications of these drugs and chemicals, there is a belief that further
information is needed to fully evaluate risks to ecosystems and human health
associated with their use in some situations. Finally, CAAP facilities also might
inadvertently introduce pathogens into receiving waters, with potentially serious
adverse impacts on native biota. This guidance document describes practices that
can be used by CAAP facilities to minimize the discharge of pollutants and
1-3
-------
SECTION 1: INTRODUCTION
minimize potential adverse impacts that pollutants might have on receiving
waters.
1.4 Current Regulatory Structure: NPDES Program
The NPDES regulations specify the applicability of the NPDES permit
requirement to concentrated aquatic animal production facilities (40 CFR 122.24
and Appendix C to Part 122). To be a concentrated aquatic animal production
facility, the facility must either meet the criteria in 40 CFR Part 122, Appendix C,
or be designated on a case-by-case basis (40 CFR 122.24(b)). A hatchery, fish
farm, or other facility is a concentrated aquatic animal production facility if it
contains, grows, or holds aquatic animals in either of two categories: cold water
or warm water. The cold water species category includes ponds, raceways, or
other similar structures which discharge at least 30 days per year, but it does not
include: facilities which produce less than 9,090 harvest weight kilograms
(approximately 20,000 pounds) per year; and facilities which feed less than 2,272
kilograms (approximately 5,000 pounds) during the calendar month of
maximum feeding. The warm water category includes ponds, raceways, or other
similar structures which discharge at least 30 days per year, but it does not
include: ponds which discharge only during periods of excess runoff; or facilities
which produce less than 45,454 harvest weight kilograms (approximately 100,000
pounds) per year (40 CFR Part 122, Appendix C).
1.5 State BMP Programs
A number of states, including Alabama, Arizona, Arkansas, Florida, Hawaii, and
Idaho, were found to have recommended BMPs for aquaculture. In addition,
BMPs have been developed for specific types of species. BMPs are addressed in
manuals or regulations, depending on the state. Data were collected from in-
house resources and through Internet research and might not represent every
state that has developed BMPs for aquaculture.
Alabama
Dr. Claude Boyd and his colleagues, with funding from the Alabama Catfish
Producers (a division of the Alabama Farmers Federation) has developed a set of
BMPs for aquaculture facilities in Alabama. The BMPs are described in a series of
guide sheets that have been adopted by USDA's Natural Resources Conservation
Service (NRCS) to supplement the Service's technical standards and guidelines
(Auburn University and USD A, 2002). The NRCS technical standards are
intended to be referenced in Alabama Department of Environmental
Management rules or requirements promulgated for aquaculture in Alabama.
The guide sheets address a variety of topics, including reducing storm runoff
into ponds, managing ponds to reduce effluent volume, controlling erosion in
1-4
-------
SECTION 1: INTRODUCTION
watersheds and on pond embankments, using settling basins and wetlands, and
implementing feed management practices.
Arizona
Arizona's regulation for BMPs for feeding operations covers aquaculture
facilities classified as feeding operations for purposes of regulation of discharge
water quality (Statutory reference: ARS 49-245-47; CWA Section 318).
The Arizona Department of Environmental Quality has rules that regulate
aquaculture through three general, goal-oriented BMPs. These BMPs address
manure handling, including harvesting, stockpiling, and disposal; treatment and
discharge of aquaculture effluents containing nitrogenous wastes; and closing of
aquaculture facilities when they cease operation (Fitzsimmons, 1999).
Compliance with these BMPs is intended to minimize the discharge of nitrates
from facilities without being too restrictive for farm operations. The draft
document Arizona Aquaculture BMPs describes BMPs that can minimize nitrogen
impacts from aquaculture facilities. A list of resources is also available for
additional information about Arizona aquaculture and BMPs (Fitzsimmons,
1999).
Arkansas
The Arkansas Bait and Ornamentals Fish Growers Association (ABOFGA)
developed a list of BMPs to help its members make their farms more
environmentally friendly. More specifically, the Association provides a set of
BMPs that help to conserve water, reduce effluent, capture solids, and manage
nutrients. Members may voluntarily agree to adopt the BMPs on their farms
(ABOFGA, n.d.). For more information, contact the University of Arkansas at
Pine Bluff.
Florida
Florida's aquaculture certificate of registration and BMP regulation requires any
person engaging in aquaculture to be certified by the Florida Department of
Agriculture and Consumer Services and to follow BMPs (Regulatory reference:
Chapter 5L-3.003,5L-3). Aquaculture Best Management Practices, a manual
prepared by the Department, establishes BMPs for aquaculture facilities in
Florida. By legislative mandate (Chapter 5L-3), the BMPs in the manual are
intended to preserve environmental integrity while eliminating cumbersome,
duplicative, and confusing environmental permitting and licensing
requirements. When these BMPs are followed, facilities meet the minimum
standards necessary for protecting and maintaining offsite water quality and
wildlife habitat. All certified aquaculturists are required to follow the BMPs in
1-5
-------
SECTION 1: INTRODUCTION
Chapters II through X of the manual, which address federal permitting;
construction; compliance monitoring; shipment, transportation, and sale; water
resources; nonnative and restricted nonnative species; health management;
mortality removal; and chemical and drug handling (FDACS, 2000).
Hawaii
Hawaii recently developed a practical BMP manual to assist aquaculture farmers
in managing their facilities more efficiently and complying with discharge
regulations. The manual, Best Management Practices for Hawaiian Aquaculture
(Howerton, 2001), is available from the Center for Tropical and Subtropical
Aquaculture.
Hawaii is also developing a BMP for traditional use of a loko kuapa-siyle
Hawaiian fish pond. Because of changes in the land tenure, decreases in native
population, total loss of traditional pond management practices, and benign
neglect, fishpond production has declined in Hawaii. Although Hawaii's
fishpond production efficiency is too low to justify the economic cost, Hawaii is
making major efforts to restore and put into service several of these traditional
structures as sustainable development demonstrations and as opportunities for
maintaining ties to a nearly extinct element of cultural heritage (SOEST, n.d.).
Idaho
In combination with site-specific information, Idaho Waste Management Guidelines
for Aquaculture Operations can be used to develop a waste management plan to
meet water quality goals. Such a waste management plan would address Idaho's
water quality concerns associated with aquaculture in response to the federal
Clean Water Act and Idaho's Water Quality Standards and Wastewater
Treatment Requirements. The manual is also intended to assist aquaculture
facility operators in developing BMPs to maintain discharge levels that do not
violate the state's water quality standards (IDEQ, n.d.).
Other BMP Guidance Documents
BMPs have also been developed for specific species, including shrimp, hybrid
striped bass, and trout. The Global Aquaculture Alliance, in Codes of Practice for
Responsible Shrimp Farming, has compiled nine recommended codes of practice
that are intended to serve as guidelines for parties who want to develop more
specific national or regional codes of practice or formulate systems of BMPs for
use on shrimp farms. These codes of practice address a variety of topics,
including mangroves, site evaluation, design and construction, feeds and feed
use, shrimp health management, therapeutic agents and other chemicals, general
pond operations, effluents and solid wastes, and community and employee
relations (Boyd, 1999). The purpose of the document is to provide a framework
1-6
-------
SECTION 1: INTRODUCTION
for environmentally and socially responsible shrimp farming that is voluntary,
proactive, and standardized. The document also provides a background
narrative that reviews the general processes involved in shrimp farming and the
environmental and social issues facing the industry (Boyd, 1999).
The Hybrid Striped Bass Industry: From Fish Farm to Consumer is a brochure that
provides guidance to new and seasoned farmers in the proper handling of fish
from the farm to the consumer. Although the brochure is primarily geared
toward providing quality fish products to consumers, the information it provides
about the use of drugs and chemicals, including pesticides and animal drugs and
vaccines, can be used to benefit the environment (Jahncke et al., 1996).
The Trout Producer Quality Assurance Program of the U.S. Trout Farmer's
Association (USTFA) is a two-part program that emphasizes production
practices that enable facilities to decrease production costs, improve
management practices, and avoid any possibilities of harmful drug or other
chemical residues in fish. Part 1 discusses the principles of quality assurance, and
Part 2 provides information about the highest level of quality assurance
endorsed by the USTFA. Although the program addresses a variety of subjects
related to trout production, the discussion on waste management and drugs and
chemicals can be applied to protecting the environment (USTFA, 1994).
1.6 Overview of Guidance Manual
The following information is discussed in detail in this manual:
• Section 2 describes a checklist of requirements under the proposed
effluent guidelines.
• Section 3 describes how to create a BMP Plan in compliance with the
proposed regulations for flow-through, recirculating, and net pen
systems.
• Section 4 describes other BMPs for all systems, including systems not
included in the scope of the proposed regulation (ponds).
• Appendix A lists additional resources available to assist facilities with
implementing BMPs.
• Appendix B is an example of a BMP plan developed by EPA and state
regulators.
• Appendix C includes fact sheets describing BMP practices.
1-7
-------
SECTION 1: INTRODUCTION
1.7 References
ABOFGA (Arkansas Bait and Ornamental Fish Growers Association). N.d. Best
Management Practices (BMP's)for Baitfish and Ornamental Fish Farms.
Arkansas Bait and Ornamental Fish Growers Association, in cooperation
with the University of Arkansas at Pine Bluff, Aquaculture/Fisheries
Center.
Auburn University and U.S. Department of Agriculture (USDA). 2002. Alabama
Aquaculture BMP fact sheets, No. 1-15.
.
Carlton, J.T., 2001. Introduced Species in U.S. Coastal Waters. Environmental Impacts
and Management Priorities. Prepared for the Pew Oceans Commission,
Arlington, VA.
FDACS (Florida Department of Agriculture and Consumer Services). 2000.
Aquaculture Best Management Practices. Florida Department of Agriculture
and Consumer Services, Division of Aquaculture, Tallahassee, Florida.
Fitzsimmons, K. 1999. Draft: Arizona Aquaculture BMPs. Arizona Department of
Environmental Quality. .
Accessed September 25,2001.
Hedrick, P.W. 2001. Invasion of transgenes from salmon or other genetically
modified organisms into natural populations. Canadian Journal of Fish.
Aquat. Sci., vol (58), 2001.
Howerton, R. 2001. Best Management Practices for Hawaiian Aquaculture.
Publication no. 148. Center for Tropical and Subtropical Aquaculture,
University of Hawaii Sea Grant Extension Services, Honolulu.
IDEQ (Idaho Division of Environmental Quality). N.d. Waste Management
Guidelines for Aquaculture Operations.
.
Accessed September 2001.
Jahncke, M.L, T.I.J. Smith, and B.P, Sheehan. 1996. The Hybrid Striped Bass
Industry: From Fish Farm to Consumer. FISMA Grant No. 12-25-G-0131. U.S.
Department of Commerce, National Marine Fisheries Service, South
Carolina Department of Natural Resources, and South Carolina
Department of Agriculture.
1-8
-------
SECTION 1: INTRODUCTION
SOEST (School of Ocean and Earth Science and Technology, Hawaii Sea Grant).
N.d. Development of a Best Management Practice for Traditional Use of A Loko
Kuapa Style Hawaiian Fishponds. School of Ocean and Earth Science and
Technology, Hawaii Sea Grant. . Accessed October 2001.
USDA (U.S. Department of Agriculture). 2000. The 1998 Census ofAquaculture.
U.S. Department of Agriculture, National Agriculture Statistics Service,
Washington, DC.
USEPA (U.S. Environmental Protection Agency). 2002. NPDES Permit no.
ME0036234. Issued by USEPA Region 1 to Acadia Aquaculture, Inc.
Signed February 21, 2002.
USTFA (U.S. Trout Farmer's Association). 1994. Trout Producer Quality Assurance
Program. U.S. Trout Farmer's Association. Charles Town, WV.
Volpe, J.P. E.B. Taylor, D.W. Rimmer, and B.W. Glickman. 2000. Evidence of
natural reproduction of aquaculture-escaped Atlantic salmon in a coastal
British Columbia river. Conservation Biology!*! (3, June): 899-903.
1-9
-------
-------
SECTION 2
REQUIREMENTS CHECKLIST FOR CAAP
FACILITIES
2.1 Introduction
EPA developed regulatory options for concentrated aquatic animal production
(CAAP) facilities with the following components:
• Management of removed solids and excess feed through treatment
technologies and best management practices (BMPs).
• A BMP plan to describe practices to minimize the potential for nonnative
species escapement and proper facility operation and maintenance.
• Drug and chemical reporting requirements.
• Active feed monitoring for net pen systems.
Table 2-1 illustrates the BMPs described under the proposed rule by subcategory.
The combinations of treatment technologies and management practices are based
primarily on the type of production system used at a facility. The type of
production system determines the relative volume and strength of wastewater
produced at a particular facility and the treatability of the wastewater using cost-
efficient treatment technologies and management practices. The size of a facility
(or production level) determines the overall volume of water discharged and
associated pollutant load. EPA used the type of production system and facility
size to determine the BMPs and treatment technologies that form the proposed
regulatory option.
Table 2-1. Production System Types and Regulatory Options
Required BMPs and
Technologies
Drug and chemical
reporting requirements
Option of alternative
compliance: TSS limits and
BMP Plan as per
requirements below OR
only a BMP plan
a. Management of removed
solids and excess feed
Flow-Through
Medium""
X
V
Large*
X
X
V
Recirculating
X
X
V
Net Pen
X
2-1
-------
SECTION 2: CHECKLIST
Required BMPs and
Technologies
b. Proper operation and
maintenance
c. Minimize potential for
escapes ofnonnatives
d. Training for staff
e. Minimize discharge of net-
fouling organisms
f. Avoid discharges of blood,
vicera, and substances
associated with washing nets
g. Prohibition of discharges of
feed bags, chemicals used to
clean nets, and materials
containing tributylin
compounds
Certification that a BMP
plan has been developed
Active feed monitoring
Flow-Through
Medium"
X
X
X
Large"
X
X
X
X
Recirculating
X
X
X
X
Net Pen
X
X
X
X
X
X
X=Required components
V=Alternative components that may not be required based on system configuration and compliance
alternative.
'Facilities producing 100,000 up to 475,000 Ibs annually are medium facilities.
'Facilities producing more than 475,000 Ib annually are large facilities.
2.2 Checklist
2.2.1 General Reporting Requirements
Under the proposed regulation, regulated facilities must notify the permitting
authority of the addition of any investigational new animal drug, any drug that
is not used according to label requirements, and any chemical that is not used
according to label requirements. (This reporting requirement does not apply to
flow-through facilities producing 100,000 to 475,000 Ib per year.) The notification
procedure is as follows:
S For drugs and chemicals not used according to label requirements, facilites
must provide an oral report to the permitting authority within 7 days after
initiating application of the drug or chemical. The oral report should identify
the drug or chemical added and the reason for adding the drug or chemical.
S For drugs and chemicals not used according to label requirements, facilities
must provide a written report to the permitting authority within 30 days after
the conclusion of the addition of the drug or chemical. The report should
identify the drug or chemical added, the reason for treatment, date(s) and
2-2
-------
SECTION 2: CHECKLIST
time(s) of the addition (including duration), the total amount of active
ingredient added, the total amount of medicated feed added (only for drugs
applied through medicated feed), and the estimated number of aquatic
animals medicated by the addition.
S For investigational new animal drugs, facilities must provide a written report
to the permitting authority within 30 days after conclusion of the addition of
the drug or chemical. The written report should identify the drug or chemical
added, the reason for treatment, date(s) and time(s) of the addition (including
duration), the total amount of active ingredient added, the total amount of
medicated feed added (only for drugs applied through medicated feed), and
the estimated number of aquatic animals medicated by the addition.
In addition to the above reporting requirements, facilities must submit a BMP
plan certification.
S The owner or operator of any facility subject to the proposed regulation must
certify that a BMP plan has been developed and that it meets the objectives as
defined in the proposed regulation.
2.2.2 Flow-Through System Requirements
Flow-through facilities subject to the proposed regulation must develop a BMP
plan to achieve some or all of the objectives and specific requirements listed
below. Checklists at the end of this section provide more details for specific
requirements based on annual production levels and facility design.
•^ Manage removed solids and excess feed by minimizing the reintroduction of
solids removed through the treatment of the water supply, and prevent excess
feed from entering the production system.
S Minimize the discharge of unconsumed food and minimize the discharge of
feeds containing high levels of fine particulates or high levels of phosphorus.
S Clean raceways at frequencies that minimize the disturbance and subsequent
discharge of accumulated solids during routine activities such as harvesting
and grading of fish.
-S Maintain in-system technologies to prevent overflow of any floating matter
and subsequent bypass of treatment technologies.
S Ensure proper storage of drugs and chemicals to avoid inadvertent spillage or
release into the aquatic animal production facility.
S Collect animal mortalities on a regular basis. Store and dispose of aquatic
animal mortalities to prevent discharge to waters of the United States.
2-3
-------
SECTION 2: CHECKLIST
S Develop and implement practices to minimize the potential escape of
normative species.
S Ensure that facility staff are familiar with the BMP plan and have been
adequately trained in specific procedures required by the plan.
2.2.3 Recirculating System Requirements
Recirculating facilities subject to the proposed regulation should develop a BMP
plan to achieve some or all of the objectives and the specific requirements listed
below. Checklists at the end of this section provide more details for specific
requirements based on annual production levels and facility design.
•^ Manage removed solids and excess feed by minimizing the reintroduction of
solids removed through the treatment of the water supply, and prevent excess
feed from entering the production system.
S Properly operate and maintain a concentrated aquatic animal production
facility by maintaining in-system technologies to prevent overflow of any
floating matter and subsequent bypass of treatment technologies.
S Ensure proper storage of drugs and chemicals to avoid inadvertent spillage or
release into the aquatic animal production facility.
S Collect animal mortalities on a regular basis. Store and dispose of aquatic
animal mortalities to prevent discharge to waters of the United States.
S Develop and implement practices to minimize the potential escape of
normative species.
-S Facilities should ensure that facility staff are familiar with the BMP plan and
have been adequately trained in specific procedures required by the plan.
2.2.4 Net Pen Requirements
Net pen facilities subject to the proposed regulation must meet the following
requirements:
-S Maintain a real-time monitoring system to monitor the rate of feed
consumption (active feed monitoring). The system should be designed to
allow detection or observation of uneaten feed passing through the bottom of
the net pens and to prevent accumulation.
S Develop a BMP plan to achieve the following objectives and requirements:
2-4
-------
SECTION 2: CHECKLIST
1. Operate the facility to minimize the concentration of net-fouling
organisms that are discharged during events such as changing and
cleaning nets and screens ashore.
2. Avoid the discharge of blood, viscera, fish carcasses, or transport
water containing blood associated with the transport or harvesting
of fish into the waters of the United States.
3. Avoid the discharge of substances associated with in-place pressure
washing nets into the waters of the United States. The use of air-
drying, mechanical, and other nonchemical procedures to control
net fouling are strongly encouraged.
4. Develop and implement practices to minimize the potential escape
of nonnative species.
5. Discharges of feed bags and other solid wastes are prohibited.
6. Discharges of chemicals used to clean nets, boats, or gear in open
waters are prohibited.
7. Discharges of materials containing or treated with tributyltin
compounds are prohibited.
2.3 References
Brown, L (ed). 1993. Aquaculture for Veterinarians: Fish Husbandry and
Medicine. Pergamon Press, Oxford.
2-5
-------
SECTION 2: CHECKLIST
CHECKLIST FOR GENERAL REPORTING REQUIREMENTS
Part A: For drugs and chemicals not used according to label requirements:
Name of drug or chemical:
Start date/time of application:
End date/time of application:
Duration:
Reason for use:
Total amount of active ingredient added:
Total amount of medicated feed added
(Only for drugs applied through medicated feed):_
Estimated total number of animals medicated by addition:
Q Oral report to permitting authority
Date and time of oral report:
Written report to permitting authority
Date and time of written report:.
DRUG/CHEMICAL
DATE
TIME
DURATION
2-6
-------
SECTION 2: CHECKLIST
CHECKLIST FOR GENERAL REPORTING REQUIREMENTS
Part B: For investigational new animal drugs:
Name of drug or chemical:
Start date/time of application:
End date/time of application:
Duration:
Reason for use:
Total amount of active ingredient added:
Total amount of medicated feed added
(Only for drugs applied through medicated feed):_
Estimated total number of animals medicated by addition:
Q Written report to permitting authority
Date and time of written report:_
DRUG/CHEMICAL
DATE
TIME
DURATION
2-7
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
WITH TSS LIMITS
Facilities with full-flow that produce 100,000 to 475,000 Ib per year
(Includes treatment from off-line settling basin that recombines
with bulk flow)
Q TSS limits (net concentrations):
Maximum Monthly Average: 6 mg/L
Maximum Daily Average: 11 mg/L
Q Develop a BMP plan with the following components:
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-8
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
FOR ALTERNATIVE COMPLIANCE WITHOUT TSS LIMITS
Facilities with full-flow that produce 100,000 to 475,000 Ib per year
(Includes treatment from off-line settling that recombines with bulk flow)
Q Develop a BMP plan with the following components:
S Description of management of removed solids and excess feed including the
following practices that meet the following components:
^ Practices that minimize the reintroduction of solids removed
through the treatment of the water supply.
^ Practices that minimize excess feed from entering the aquatic
animal production system.
^ Practices that minimize the discharge of feed containing high
levels of fine particulates or high levels of phosphorus.
^ Description of raceway cleaning practices that minimize the
disturbance and subsequent discharge of accumulated solids
during routine activities, such as harvesting and grading of fish.
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-9
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
WITH TSS LIMITS
Facilities with a separate off-line settling basin (OLSB)
that produce 100,000 to 475,000 Ib per year
(Includes facilities that discharge from OLSB separate from bulk discharge)
Q TSS limits (net concentrations) for OLSB discharge only:
Maximum Monthly Average: 67 mg/L
Maximum Daily Average: 87 mg/L
Q Develop a BMP plan with the following components:
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Q For bulk discharge, develop a BMP plan with the following components:
Description of management of removed solids and excess feed including the
following practices that meet the following components:
-S Practices that minimize the reintroduction of solids removed through the
treatment of the water supply.
S Practices that minimize excess feed from entering the aquatic animal
production system.
-S Practices that minimize the discharge of feed containing high levels of fine
particulates or high levels of phosphorus.
2-10
-------
SECTION 2: CHECKLIST
S Description of raceway cleaning practices that minimize the disturbance and
subsequent discharge of accumulated solids during routine activities, such as
harvesting and grading of fish.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-11
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
FOR ALTERNATIVE COMPLIANCE WITHOUT TSS LIMITS
Facilities with a separate off-line settling basin (OLSB)
that produce 100,000 to 475,000 Ib per year
(Includes facilities that discharge from OLSB separate from bulk discharge)
Q Develop a BMP plan with the following components:
-S Description of management of removed solids and excess feed including the
following practices that meet the following components:
^ Practices that minimize the reintroduction of solids removed
through the treatment of the water supply.
^ Practices that minimize excess feed from entering the aquatic
animal production system.
^ Practices that minimize the discharge of feed containing high
levels of fine particulates or high levels of phosphorus.
^ Description of raceway cleaning practices that minimize the
disturbance and subsequent discharge of accumulated solids
during routine activities, such as harvesting and grading of fish.
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-12
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
WITH TSS LIMITS
Facilities with full-flow that produce more than 475,000 Ib per year
(Includes treatment from off-line settling basin that recombines
with bulk flow)
Q TSS limits (net concentrations):
Maximum Monthly Average: 6 mg/L
Maximum Daily Average: 10 mg/L
Q Develop a BMP plan with the following components:
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Description of practices to minimize the potential escape of normative species
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Q Drug and chemical reporting requirements.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-13
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
FOR ALTERNATIVE COMPLIANCE WITHOUT TSS LIMITS
Facilities with full-flow that produce more than 475,000 Ib per year
(Includes treatment from off-line settling that recombines with bulk flow)
I Develop a BMP plan with the following components:
-S Description of management of removed solids and excess feed including the
following practices that meet the following components:
^ Practices that minimize the reintroduction of solids removed
through the treatment of the water supply.
^ Practices that minimize excess feed from entering the aquatic
animal production system.
^ Practices that minimize the discharge of feed containing high
levels of fine particulates or high levels of phosphorus.
^ Description of raceway cleaning practices that minimize the
disturbance and subsequent discharge of accumulated solids
during routine activities, such as harvesting and grading of fish.
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Description of practices to minimize the potential escape of normative species
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
I Drug and chemical reporting requirements.
2-14
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
WITH TSS LIMITS
Facilities with a separate off-line settling basin (OLSB)
that produce more than 475,000 Ib per year
(Includes facilities that discharge from OLSB separate from bulk discharge)
TSS limits (net concentrations) for OLSB discharge only:
Maximum Monthly Average: 55 mg/L
Maximum Daily Average: 69 mg/L
Develop a BMP plan with the following components:
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Description of practices to minimize the potential escape of normative species.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
For bulk discharge, develop a BMP plan with the following components:
S Description of management of removed solids and excess feed including the
following practices that meet the following components:
^ Practices that minimize the reintroduction of solids removed
through the treatment of the water supply.
^ Practices that minimize excess feed from entering the aquatic
animal production system.
^ Practices that minimize the discharge of feed containing high
levels of fine particulates or high levels of phosphorus.
2-15
-------
SECTION 2: CHECKLIST
^ Description of raceway cleaning practices that minimize the
disturbance and subsequent discharge of accumulated solids
during routine activities, such as harvesting and grading of fish.
Q Drug and chemical reporting requirements.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-16
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR FLOW-THROUGH SYSTEMS
FOR ALTERNATIVE COMPLIANCE WITHOUT TSS LIMITS
Facilities with a separate off-line settling basin (OLSB) that produce more than
475,000 Ib per year (Includes facilities that discharge from OLSB separate
from bulk discharge)
Q Develop a BMP plan with the following components:
-S Description of management of removed solids and excess feed including the
following practices that meet the following components:
^ Practices that minimize the reintroduction of solids removed
through the treatment of the water supply.
^ Practices that minimize excess feed from entering the aquatic
animal production system.
^ Practices that minimize the discharge of feed containing high
levels of fine particulates or high levels of phosphorus.
^ Description of raceway cleaning practices that minimize the
disturbance and subsequent discharge of accumulated solids
during routine activities, such as harvesting and grading of fish.
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Description of practices to minimize the potential escape of normative species.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
2-17
-------
SECTION 2: CHECKLIST
Q Drug and chemical reporting requirements.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-18
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR RECIRCULATING SYSTEMS
WITH TSS LIMITS
Facilities that produce 100,000 Ib or more per year
Q TSS limits (net concentrations) for all discharges:
Maximum Monthly Average: 30 mg/L
Maximum Daily Average: 50 mg/L
Q Develop a BMP plan with the following components:
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals that avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis and to
store and dispose of mortalities to prevent discharge to waters of the United
States.
S Description of practices that minimize the potential escape of normative
species.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Q Drug and chemical reporting requirements.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-19
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR RECIRCULATING SYSTEMS
FOR ALTERNATIVE COMPLIANCE WITHOUT TSS LIMITS
Facilities that produce 100,000 Ib or more per year
Q Develop a BMP plan with the following components:
S Description of management of removed solids and excess feed including the
following practices that meet the following components:
^ Practices that minimize the reintroduction of solids removed
through the treatment of the water supply.
^ Practices that minimize excess feed from entering the aquatic
animal production system.
^ Practices that minimize the discharge of feed containing high
levels of fine particulates or high levels of phosphorus.
^ Description of raceway cleaning practices that minimize the
disturbance and subsequent discharge of accumulated solids
during routine activities, such as harvesting and grading of fish.
S Description of practices that maintain in-system technologies to prevent
overflow of floating matter and subsequent bypass of treatment technologies.
S Description of storage practices for drugs and chemicals to avoid inadvertent
spillage or release into the aquatic animal production facility.
S Description of practices to collect animal mortalities on a regular basis, and
practices to store and dispose of mortalities to prevent discharge to waters of
the United States.
S Description of practices to minimize the potential escape of normative species.
S Discussion of training and briefing for staff regarding specific procedures
required by the BMP plan.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Q Drug and chemical reporting requirements.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-20
-------
SECTION 2: CHECKLIST
REQUIREMENTS FOR NET PEN SYSTEMS
Facilities that produce 100,000 Ib per year or more, except net pen facilities
located in the State of Alaska producing native species of salmon
Q Maintain real-time monitoring system to monitor the rate of feed
consumption.
Q Develop a BMP plan to meet the following requirements and objectives:
S Operate the facility to minimize the concentration of net-fouling organisms
that are discharged during events such as changing and cleaning nets and
screens ashore.
S Avoid the discharge of blood, viscera, fish carcasses, or transport water
containing blood associated with the transport or harvesting of fish into the
waters of the United States
S Avoid the discharge of substances associated with pressure-washing nets into
the waters of the United States. The use of air-drying, mechanical and other
nonchemical procedures to control net fouling are strongly encouraged.
S Develop and implement practices to minimize the potential escape of
normative species.
S Discharges of feed bags and other solid wastes into the waters of the United
States are prohibited.
S Discharges of chemicals used to clean nets, boats, or gear into the waters of the
United States are prohibited.
S Discharges of materials containing or treated with tributyltin compounds into
the waters of the United States are prohibited.
S Certification by owner or operator of the facility that a BMP plan has been
developed and that it meets the objectives as defined in the proposed
regulation.
Q Drug and chemical reporting requirements.
Refer to Section 3 for more detail on how to write a BMP plan and Appendix B
for an example of a BMP plan.
2-21
-------
SECTION 2: CHECKLIST
CALCULATING MEDICATED FEED CONTENT
Drug treatments for aquaculture operations are commonly added to the diet to
reduce the labor involved with administering the treatment. Fish requiring drug
treatment are considered to have reduced appetites and therefore are commonly
fed at only 1% of their estimated body weight per day. The amount drug added
to feed varies depending on the severity of the infection and type of drug used. A
common treatment level for oxytetracycline is 75 mg/kg (Brown, 1993).
Pounds of feed per day * dosage * conversion factor
Where
Pounds of feed per day = daily feeding levels (Ibs)
Dosage = amount of drug in a given mass of feed (mg drug/kg feed)
Conversion factor = 0.4536 kg/lb
An example calculation for a drug treatment of oxytetracycline at 75 mg/kg for
5000 Ib of fish at a feed rate of 1% per day is presented below.
5000 Ib fish * 1% feed rate = 50 Ib feed per day
50 Ib feed * 0.4536 kg/lb (conversion factor) * 75mg/kg dosage = 0.0037 Ib
of oxytetracycline per day.
Where
Feed rate = the amount of feed offered per day based on a percentage of
body weight
2-22
-------
SECTION 3
How TO WRITE A BMP PLAN
3.1 Introduction
A best management practice (BMP) is a practice or combination of practices that
provide an effective means of preventing or reducing levels of pollutants in
facility discharges.
Facility operators design BMP plans to include a series of practices such as health
management, feed management, effluent discharge management, and drug and
chemical use. BMP plans are flexible and allow facility operators to design
measures and practices that work within their facility management framework.
In the context of the CAAP proposed effluent guidelines, the BMP plan includes
components that are designed to minimize the discharge of solids from the
facility. The goal of this plan is to control conventional and nutrient pollutants in
the discharge. The CAAP facility is expected to provide written documentation
of a best management plan and keep necessary records to demonstrate the
implementation of the plan. This type of regulatory structure allows individual
facilities to develop a plan tailored to the unique conditions of the CAAP facility,
while reducing the discharge of pollutants consistent with the goals of the Clean
Water Act.
3.2 Guidance for Developing a BMP Plan
The goal of a BMP plan is to describe the standard operating procedures and
BMPs used to minimize, collect, and dispose of pollutants generated during
facility operation.
The following components are based on information from requirements in
existing NPDES permits (USEPA Regions 1 and 10) for CAAP facilities in Idaho
(USEPA, 1999), Maine (USEPA, 2002), and Massachusetts (USEPA, 2001). A BMP
plan for CAAP facilities should include the following components:
1. Management of removed solids and excess feed (only for facilities under
alternative compliance without TSS limits.)
a. Describe pollution control equipment or methods used to enhance solids
collection, (e.g. quiescent zones, settling basins)
b. Describe how excessive solids buildup will be identified to trigger more
frequent cleaning of raceways/culture tanks and equipment to prevent
more suspended and dissolved materials in the discharge.
3-1
-------
SECTION 3: How TO WRITE A BMP PLAN
c. Describe feeding methods used to minimize the amount of feed and
residual in the discharge.
d. Describe the preventive maintenance program for cleaning equipment
used for cleaning culture units so that delays in cleaning due to
equipment failure are avoided.
e. Describe inputs and outputs from the facility including water, dissolved
pollutants, solids, fish, feed, and mortalities due to predation or disease.
f. Describe the cleaning of culture tanks/raceways and other equipment and
how practices minimize the disturbance and subsequent discharge of
accumulated solids during routine activities such as harvesting and
grading of fish.
2. Proper operation and maintenance of a CAAP facility
a. Describe maintenance procedures for in-system technologies to prevent
the overflow of any floating matter and subsequent by-pass of treatment
technologies.
b. Describe the proper storage of drugs and chemicals to avoid the
inadvertent spillage or release into the aquatic animal production facility.
c. Describe the collection of aquatic animal mortalities, the frequency of the
collections, and how mortalities are stored and disposed to prevent
discharge into the waters of the United States.
3. Practices to minimize the potential escape of nonnative species (not
applicable to flow-through facilities producing 100,000 to 475,000 Ib per year.)
a. Describe in detail precautions taken by the facility to prevent the loss of
nonnative species. This description should include a schedule for
preventive maintenance and inspection of the containment system, escape
recovery protocols, and fish transfer procedures during stocking and
grading.
b. For net pen systems, describe secondary containment equipment.
Secondary containment involves the use of a second set of containment
netting around a net pen system. The secondary containment netting
should be positioned to capture any fish that might escape the primary
containment netting because of damage to the net pen system that could
occur during a storm event or other structural failure.
3-2
-------
SECTION 3: How TO WRITE A BMP PLAN
4. Personnel training. Describe the training to be provided for employees to
ensure that they understand the goals and objectives of BMPs and their role
in complying with the goals and objectives of the BMP plan.
5. For net pen facilities, describe practices to minimize the discharge of net-
fouling organisms, the prevention of discharges of blood, viscera, and fish
carcasses associated with the transport and harvest of fish, the prevention of
discharges of substances associated with in-place pressure washing of nets,
and the prevention of discharges of feed bags, chemicals used to clean nets
and gear, and materials containing tributyltin compounds.
6. Include a statement certifying that the facility manager and the individuals
responsible for implementing of the BMP plan have reviewed and endorsed
the plan.
Implementation Notes
Include a diagram or map of the facility to illustrate the layout of the
operation.
(See sample BMP plan in Appendix B.)
Additional Resources
IDEQ (Idaho Division of Environmental Quality). N.d. Waste Management
Guidelines for Aquaculture Operations. Boise, ID.
.
Accessed September 2001.
Summerfelt, S.T., and B.J. Vinci. 2002. Best waste management practices for
coldwater recirculating systems. In Proceedings of The Fourth International
Conference on Recirculating Aquaculture, ed. T.T. Rakestraw, L.S. Douglas,
and G.J. Flick, pp. 375-381. Roanoke, VA, July 18-21, 2002.
USTFA (U.S. Trout Farmer's Association). 1994. Trout Producer Quality Assurance
Program. U.S. Trout Farmer's Association. Charles Town, WV.
3-3
-------
SECTION 3: How TO WRITE A BMP PLAN
CHECKLIST FOR BMP PLAN
WITH TSS LIMITS
Proper operation and maintenance of a CAAP facility
Q Description of maintenance procedures for in-system technologies to
prevent the overflow of any floating matter and subsequent by-pass of
treatment technologies.
Q Description of proper storage of drugs and chemicals to avoid the
inadvertent spillage or release into the aquatic animal production facility.
Q Description of the collection of aquatic animal mortalities, the frequency
of collections, and how mortalities are stored and disposed to prevent
discharge into the waters of the United States.
Practices to minimize potential escape of nonnative species
Q Description of precautions taken by the facility to prevent the loss of
nonnative species.
Q Description of containment system.
Q Escape recovery protocols.
Q Fish transfer procedures used during stocking and grading.
Personnel training
Q Training for employees to learn procedures for BMPs.
Q Assurance that employees understand their role in complying with the
objectives of the BMP plan.
Statement of BMP review and endorsement
Q Statement of certification signed by facility manager or individuals
responsible for implementation of the BMP plan.
CHECKLIST FOR BMP PLAN
UNDER ALTERNATIVE COMPLIANCE WITHOUT TSS LIMITS
Management of removed solids and excess feed
Q Description of pollution control equipment and solids collection.
Q Explanation of how excessive solids buildup will trigger more frequent
cleanings of raceways or culture units.
3-4
-------
SECTION 3: How TO WRITE A BMP PLAN
Q Description of feed management practices used to minimize the amount
of excess feed.
Q Description of preventive maintenance program used to prevent delays in
cleaning due to equipment failure.
Q Description inputs and outputs from the facility, including water,
dissolved pollutants, solids, fish, feed, and mortalities.
Q Describe the cleaning of culture tanks or raceways another other
equipment and how practices minimize the disturbance and subsequent
discharge of accumulated solids during routine activities such as
harvesting and grading of fish.
Proper operation and maintenance of a CAAP facility
Q Description of maintenance procedures for in-system technologies to
prevent the overflow of any floating matter and subsequent by-pass of
treatment technologies.
Q Description of proper storage of drugs and chemicals to avoid the
inadvertent spillage or release into the aquatic animal production facility.
Q Description of the collection of aquatic animal mortalities, the frequency
of collections, and how mortalities are stored and disposed to prevent
discharge into the waters of the United States.
Practices to minimize potential escape of nonnative species
Q Description of precautions taken by the facility to prevent the loss of
nonnative species.
Q Description of containment system.
Q Escape recovery protocols.
Q Fish transfer procedures used during stocking and grading.
For net pen facilities
Q Operate the facility to minimize the concentration of net-fouling
organisms that are discharged during events such as changing and
cleaning nets and screens ashore.
Q Avoid the discharge of blood, viscera, fish carcasses, or transport water
containing blood associated with the transport or harvesting of fish into
the waters of the United States
Q Avoid the discharge of substances associated with pressure-washing nets
into the waters of the United States. The use of air-drying, mechanical and
3-5
-------
SECTION 3: How TO WRITE A BMP PLAN
other nonchemical procedures to control net fouling are strongly
encouraged.
Q Develop and implement practices to minimize the potential escape of
nonnative species.
Q Discharges of feed bags and other solid wastes into the waters of the
United States are prohibited.
Q Discharges of chemicals used to clean nets, boats, or gear into the waters
of the United States are prohibited.
Q Discharges of materials containing or treated with tributyltin compounds
into the waters of the United States are prohibited.
Personnel training
Q Training for employees to learn procedures for BMPs.
Q Assurance that employees understand their role in complying with the
objectives of the BMP plan.
Statement of BMP review and endorsement
Q Statement of certification signed by facility manager or individuals
responsible for implementation of the BMP plan.
3-6
-------
SECTION 3: How TO WRITE A BMP PLAN
3.3 Guidance for Drug and Chemical Reporting Requirements
The goal of drug and chemical reporting requirements is to minimize drug and
chemical discharges from a facility. Reporting requirements include the
following:
1. For a written report for drugs and chemicals not used according to label
requirements, list the following information:
• Product name of the drug or chemical.
• Reason for treatment
• Dates and times of the addition (including duration).
• The total amount of active ingredient added.
• The total amount of medicated feed added (only for drugs applied
through medicated feed).
• Estimated number of aquatic animals medicated by the addition.
Submit written report within 30 days after conclusion of the addition of the drug
or chemical.
Provide an oral report to the permitting authority within 7 days after initiating
application of a drug or chemical that is not used according to label
requirements.
2. For a written report for investigational new animal drugs, list the following
information:
• Product name of the drug or chemical.
• Reason for treatment
• Dates and times of the addition (including duration).
• The total amount of active ingredient added.
• The total amount of medicated feed added (only for drugs applied
through medicated feed).
• Estimated number of aquatic animals medicated by the addition
3-7
-------
SECTION 3: How TO WRITE A BMP PLAN
Submit written report within 30 days after conclusion of the addition of the drug
or chemical.
Implementation Notes
1. For drug and chemical use and handling, keep original containers, and
purchase and mix only the necessary amounts to reduce storage requirements
and avoid potential leaks or spills.
2. Store drugs and chemicals in a designated space away from rearing areas,
feeds, and water sources. Avoid storage areas with drains; this will help
contain a spill if one should occur.
3. Use drugs or chemicals only as directed on the label.
4. Educate personnel on proper handling, use, and spill containment
procedures.
5. Maintain accurate records for treatment application.
Additional Resources
The U.S. Food and Drug Administration Web site has more information on drug
and chemical use in aquaculture:
http://www.fda.gov/cvm/index/aquaculture/appendixa6.htm
3.4 References
USEPA (U.S. Environmental Protection Agency). 1999. NPDES Permit no. ID-
G13-0000. Issued by USEPA Region 10 to Aquaculture Facilities in Idaho.
Signed September 10,1999.
USEPA (U.S. Environmental Protection Agency). 2001. NPDES Permit no.
MA0005916. Issued by USEPA Region 1 to Woods Hole Oceanographic
Institution, Environmental Systems Laboratory.
USEPA (U.S. Environmental Protection Agency). 2002. NPDES Permit no.
ME0036234. Issued by USEPA Region 1 to Acadia Aquaculture, Inc.
Signed February 21, 2002.
3-8
-------
SECTION 4
BMPs FOR CAAP FACILITIES
4.1 Introduction
The following section describes BMPs for the CAAP industry. Practices for the
following CAAP activities are provided:
4.2 Feed Management
4.3 Designing and Maintaining Quiescent Zones
4.4 Designing and Maintaining Sedimentation Basins (Primary Settling)
4.5 Secondary Settling with Microscreens
4.6 Secondary Settling with Vegetated Ditches
4.7 Secondary Settling with Constructed Wetlands
4.8 Solids Disposal
4.9 Active Feed Monitoring
4.10 Practices to Minimize the Potential Escape of Nonnative Species
4.12 Net Pen Siting
4.13 Net Cleaning
4.14 Discharge Management
4.15 Erosion Control
4.16 Managing Rainwater and Reducing Overflow
4.17 Using Drugs and Chemicals: Fertilizers, Therapeutic Agents, and
Water Quality Enhancers for Ponds
4.18 Oxidation Lagoons
4.19 References
Each section describes the practice and guidance for its implementation. Each
practice also includes a summary of systems for which the practices are
applicable.
4.2 Feed Management
Systems: Pond, flow-through, recirculating, net pens, and alligators
Feed is the primary input of pollutants to CAAP systems. Feed management
recognizes the importance of effective, environmentally sound use of feed.
Facility operators should continually evaluate their feeding practices to ensure
that feed placed in the system is consumed at the highest rate possible. For all
systems, observing feeding behavior and noting the presence of excess feed can
be used to adjust feeding rates to ensure maximum feed consumption and
minimal excess.
4-1
-------
SECTION 4: BMPs FOR CAAP FACILITIES
The primary operational factors associated with proper feed management are
development of precise feeding regimes based on the weight of the cultured
species and regular observation of feeding activities to ensure that the feed
offered is consumed. An advantage of this practice is that proper feed
management decreases the costs associated with the use of excess feed that is
never consumed by the cultured species. Excess feed distributed to systems
breaks down, and some of the resulting products remain dissolved in the system
water.
Guidance for Flow-through and Recirculating Systems
1. Avoid overfeeding fish. Regardless of the delivery system, focus on
directing feed to the fish.
2. Store feed properly to reserve the nutrient quality. Minimize humidity to
prevent growth of molds or bacteria on feed. Follow manufacturers'
recommendations for feed shelf life.
3. Handle feed with care to prevent fines. If fines are present, remove and
dispose of them properly.
4. Know the feed requirements of the cultured species to determine the
percentage of body weight per day. Use size of fish, water temperature,
projected growth rates, and biomass in the system to determine
appropriate feeding rates (Westers, 1995).
5. Use high-quality feeds to improve feed conversion and efficient use of
nutrients.
6. Observe feeding behavior to monitor feed utilization.
Implementation Notes
• Feed only the amount that will be consumed in 20 minutes. (US Trout
Farmers Association, 1994).
• Use feed delivery systems that have devices for the removal of fine
particles from feed.
• Generally, frequent feedings of smaller amounts are better than giving the
day's ration in a few feedings (IDEQ, n.d.)
• Oxygen levels drop dramatically where large amounts of feed are fed at
one time.
• Fish should be fed during the coolest parts of the day in hot weather;
reduce feeding when water temperatures reach 65-70 °F for trout. Feeding
4-2
-------
SECTION 4: BMPs FOR CAAP FACILITIES
in low-oxygen environments reduces dietary efficiency and can result in
fish health problems.
• Use of demand feeders allows fish to set the frequency and duration of
feeding.
• Blowers, as well as automated delivery systems that supply discrete
amounts of feed frequently over a long period of time, may also be used to
distribute feed in raceways or tanks.
• Regardless of the method of feed distribution, it is important to observe
feeding behavior and prevent overfeeding.
• Overfeeding can affect the health of the fish by contributing to liver and
kidney problems.
• Excess feed results in economic losses and degrades water quality, which
can adversely affect the health of the aquatic animals.
Guidance for Pond Systems
The following is based on guidance from Alabama aquaculture BMP fact sheet
BMP No. 7, "Feed Management" (Auburn University and USD A, 2002g).
1. Use high-quality feed that contains adequate, but not excessive, nitrogen
and phosphorus.
2. Protect feed quality by storing feed in well-ventilated, dry bins or, if
bagged, in a well-ventilated, dry room. Always use fresh feed to maximize
the efficiency with which fish can use it.
3. Apply feed uniformly across the surface of the pond using a mechanical
feeder.
4. Do not overfeed fish. Avoid overfeeding by observing fish feeding
behaviors. Do not apply more feed than the fish will eat.
5. Maintain adequate levels of dissolved oxygen. Fish stressed by poor water
quality conditions will be less efficient in their ability to convert feed to
flesh.
6. For daily feed applications in catfish ponds, do not exceed 30 Ib/ac in
unaerated ponds. In ponds with 2 hp of aeration per acre, daily feed
applications can be increased to 100 to 120 Ib/ac. These feed amounts are
maximum amounts to be applied on a given day, not annual averages.
4-3
-------
SECTION 4: BMPs FOR CAAP FACILITIES
Implementation Notes
• Because feed management is the main source of nutrients in the pond
systems, good feed management, reasonable stocking rates, and adequate
aeration are effective tools for enhancing effluent quality.
• Percentages of 4.5% to 5.1% (28% to 32% crude protein) for nitrogen and
0.75% to 1.0% phosphorus are acceptable levels of these elements in feeds
for growout.
• Mechanical feeders dispense feed evenly around the edges of the pond to
ensure that fish have an opportunity to eat an adequate amount of feed.
• One sign of overfeeding is the accumulation of feed in the corners of the
pond.
• Overfeeding is costly and results in unnecessary nutrient inputs into the
pond.
• Several factors influence feed consumption, including water temperature,
poor environmental conditions like low levels of dissolved oxygen or high
concentrations of ammonia, and disease or parasite problems.
• Mechanical aeration prevents low dissolved oxygen concentrations,
thereby avoiding fish stress and improving the effectiveness of the pond
to assimilate wastes from feeding, ensuring the water quality of the pond
and the effluent.
Guidance for Net Pen Systems
In addition to the above practices, feed management practices for net pen
facilities should a real-time monitoring system to monitor the rate of feed
comsumption. Excess feed is the primary source of sediment accumulation
beneath net pens, which can have an adverse effect on the benthic community.
Refer to section 4.9 for more detail.
4.3 Designing and Maintaining Quiescent Zones
Systems: Flow-through
Quiescent zones are used in raceway flow-through systems (typically concrete
raceways) in which the last approximately 10% of the raceway serves as a
settling area for solids.
Quiescent zones usually are constructed with a wire mesh screen that extends
from the bottom of the raceway to above the maximum water height to prevent
the cultured species from entering the quiescent zone. Reducing the turbulence
usually caused by the swimming action of the cultured species allows the solids
to settle in the quiescent zone. The collected solids are then available to be
efficiently removed from the system.
4-4
-------
SECTION 4: BMPs FOR CAAP FACILITIES
Guidance
The following design guidance is based on the Idaho Waste Management Guidelines
for Aquaculture Facilities (IDEQ, n.d.).
1. A quiescent zone (QZ) is a settling zone; therefore, the dimensions of the
QZ must be adequate to ensure that the overflow rate (V0) is smaller than
the settling velocity (Vs):
V0 = ft3/s/ft2 or cubic feet per second of flow per square foot of settling
area = ft/s (velocity)
Vs = settling velocity of biosolids in feet per seconds
2. The accepted range of Vs values for biosolids in raceways is 0.031 ft/s to
0.164 ft/s, so the dimensions for QZs should provide a V0 value smaller
than 0.031 ft/s.
3. Widths of troughs or raceways and their QZs are usually proportional to
flow rate, which is directly related to the amount of fish that the rearing
area will support.
4. Example: A QZ with a width of 18 feet, a length of 20 feet, and a flow of
6cfs has an overflow rate (V0) of 0.017 ft/s. This value is just over half of
the lower range for Vs values of QZs, meeting the criteria for QZ
dimensions.
5. Other design options: sloped, recessed floors of QZ. (See Idaho Wastewater
Management Guidelines for more detail.)
6. The most common method of solids removal from QZs is by suction
through a vacuum head. Facilities may use standpipes in each QZ to
connect to a common 4-to 8-in. PVC pipe that carries the slurry of water
and solids to the off-line settling basin. Suction is provided by head
pressure from the raceway water depth and by gravity, or by pumps.
7. Slurry transport pipes and pumps should be properly sized to carry the
required flow and provide adequate suction. Without adequate suction,
the vacuum head will resuspend the particles before they can be
vacuumed. To operate a 12- to 18-in. wide vacuum head, 100 gpm is ideal.
8. Pumps should be designed to handle 12% solids, moss, leaves, and other
debris, which might collect in the QZ.
9. Where lift is needed, it is more efficient and cost-effective to connect pipes
from several QZs by gravity flow to a sump or lift station with a
4-5
-------
SECTION 4: BMPs FOR CAAP FACILITIES
stationary pump than it is to move a portable pump from one QZ to
another.
10. Design piping systems to minimize settling of solids within the pipes.
Consider clean-outs throughout the piping system. Long-radius bends are
better than short radius bends. Pipes should be sloped to provide
adequate cleaning velocities.
11. Design system hydraulics to prevent system components from freezing.
12. Consider spare parts for key equipment and a contingency plan for
maintaining compliance in the event of equipment failures.
13. Consider the use of baffles in the raceway or trough to direct water flow.
Water flows underneath the baffles, increasing flow velocity along the
bottom of the pond or raceway and moving solids downstream where
they can be collected in QZs. Placement of baffles varies with raceway or
pond dimensions, flow, and fish size.
Implementation Notes
• The settled solids should be removed regularly so they cannot become
entrained in the wastewater flow and contribute to the pollutant loadings
of the facility. Two operational factors associated with operating QZs are
(1) the necessity to clean the screens, and (2) the regular removal of
collected solids from the QZs.
• QZs should be cleaned as frequently as possible, at least once every 2
weeks (IDEQ, n.d.)
• Screens separating the rearing area from the QZ should be cleaned daily
to promote laminar flow.
• System designs that provide gentler handling of solids are better preferred
because systems where more turbulence occurs need larger settling areas
to compensate for the settling requirement of small particles.
• System designs that allow for frequent or continuous harvest of solids are
preferable and should require smaller settling zones.
• Rectangular settling zones or quiescent zones promote flow that is evenly
distributed over the entire surface area (laminar flow).
• Cleaning of the QZs also creates a highly concentrated waste stream that
should be treated before it is discharged into a receiving water body.
4-6
-------
SECTION 4: BMPs FOR CAAP FACILITIES
4.4 Designing and Maintaining Sedimentation Basins (Primary Settling)
Systems: Ponds, flow-through, and recirculating
Sedimentation basins separate solids from water using gravity settling of the
heavier solid particles (Metcalf and Eddy, 1991). In the simplest form of
sedimentation, particles that are heavier than water settle to the bottom of a tank
or basin. Periodically, the basin is cleaned of the accumulated solids.
Sedimentation basins (also called settling basins, settling ponds, sedimentation
ponds, or sedimentation lagoons) are used extensively in the wastewater
treatment industry and are commonly found in many flow-through AAP
facilities. Most sedimentation basins are used to produce a clarified effluent (for
solids removal), but some sedimentation basins remove water from solids to
produce a more concentrated sludge.
How Sedimentation Basins Work
Settling in sedimentation basins occurs when the horizontal velocity of a particle
entering the basin is less than the vertical (settling) velocity in the tank. The
settling properties of an effluent, particularly the settling velocities, are
determined and sedimentation basins are sized to accommodate the expected
flow through the basin. The length of the sedimentation basin and the detention
time can be calculated so that particles with a particular settling velocity will
settle to the bottom of the basin (Metcalf and Eddy, 1991).
Other design factors include the effects of inlet and outlet turbulence, short-
circuiting of flows within the basin, solids accumulation in the basin, and
velocity gradients caused by disturbances within the basin (such as those from
solids removal equipment).
Guidance for Flow-Through Systems
For flow-through systems, there are two types of settling basins: off-line settling
(OLS) basins and full-flow settling (FES) basins. Off-line settling basins are
settling zones that receive water and solids slurry removed from QZs and
rearing areas. These basins are the second settling area in the solids collection
system after QZs. QZs in combination with OLS basins are the most commonly
used solids collection system (IDEQ, n.d). A full-flow settling basin may not
include QZs; instead, this system has one or two large settling areas that collect
solids from the water flow from the entire facility. Solids might not be removed
from individual rearing units.
OLS basins
1. Solid entering OLS basins are usually smaller because of the turbulence
associated with the pumps and pipes that carry solids from the QZs. The
range of accepted Vs value range for these smaller particles is 0.00151 ft/s
4-7
-------
SECTION 4: BMPs FOR CAAP FACILITIES
to 0.00302 ft/s. The V0 value for OLS should be less than 0.00151 ft/s
(IDEQ, n.d.)
2. OLS basins are usually 3.5 ft deep but may be deeper. Depth is not
required for settling efficiency, but it is required for solids storage. (A
depth of 3.5 ft provides adequate storage if solids are removed monthly
(IDEQ, n.d.).
3. Facilities may also use several OLS basins to improve solids removal
efficiency. When one basin is undergoing solids harvesting, flow can be
redirected to another basin (IDEQ, n.d.). Multiple OLS basins may be
operated in a series or in parallel. Basins linked in a series generally have a
V0 value smaller than 0.00151 ft/s. Basins linked in parallel divide the flow
and reduce the water velocity, which improves the Vo and weir rate.
FFS basins
1. Solids particles flowing to FFS basin systems are larger than solids in OLS
basins because they are exposed to less turbulence, but they are smaller
than solids from QZs. The recommended V0 value for FFS basins is 0.013
ft/s or less (IDEQ, n.d.).
2. The design should include a bypass channel for the FFS basin so solids can
be removed (IDEQ, n.d.).
3. FFS systems should include two basins operated in parallel so that one
basin remains operational when solids are being harvested from the other
basin (IDEQ, n.d.).
Implementation Notes
• System operators should attempt to minimize the breakdown of particles
(into smaller sizes) to maintain or increase the efficiency of sedimentation
basins (IDEQ, n.d.).
• Proper design, construction, and operation of the sedimentation basin are
essential for the efficient removal of solids (IDEQ, n.d.).
• Solids must be removed at proper intervals to ensure the designed
removal efficiencies of the sedimentation basin. For both OLS and FFS
basins, IDEQ recommends a minimum harvest frequency of every 6
months. Infrequent harvests could result in the breakdown of solids and
the release of dissolved nutrients into the receiving waters.
• FFS basins are most commonly used at smaller facilities with low flow
volumes.
4-8
-------
SECTION 4: BMPs FOR CAAP FACILITIES
• For FFS basins, some facilities might batch crop their fish so that they can
all be harvested at the same time. Then solids can be harvested from the
FFS basins when the facility is empty (IDEQ, n.d.).
4.5 Secondary Settling with Microscreen Filters
Systems: Flow-through and recirculating
Solids polishing is the use of a secondary wastewater treatment technology to
further reduce solids discharged from flow-through systems. Several
technologies are available, including microscreen filters, vegetated ditches, and
constructed wetlands. Microscreen filters are fine mesh filters with automatic
backwash that collect solids. Polishing ponds are secondary sedimentation basins
used to settle solids from the discharge of the primary sedimentation basin.
Microscreen filters are commonly used filtration systems that consist of a
synthetic screen of specific pore size that is used to remove solids from the
effluent stream. Pore sizes for microscreen filters vary from 15 to 60
micrometers(Lim)(Metcalf and Eddy, 1991). Most microscreen filters operate by
pumping the wastewater stream into a space inside the filter. The water passes
through the screen and solids are trapped inside the screen. The solids can be
discharged to further treatment or to a solids holding unit.
Guidance
1. Microscreening involves the use of variable low-speed (up to 4
revolutions/min), continuously backwashed, rotating drum filters
operating under gravity conditions. The wastewater enters the open end
of the drum and flows outward through the rotating screening cloth. The
solids are backwashed by high-pressure jets into a trough located within
the drum (Metcalf and Eddy, 1991).
2. Typical values for design parameters:
a. Screen size: 15 to 60 |im
Stainless steel or polyester screen cloths are
available in sizes ranging from 15 to 60 |im
c. Hydraulic loading: 75 to 150 gal/ft2/nvin
d. Drum diameter: 8 to 16 ft
d. Drum submergence: 70% to 75% of height; 60% to 70% of area
e. Drum speed: 15 ft/min at 3-in. headloss; 115 to 150
ft/min at 6-in headloss.
4-9
-------
SECTION 4: BMPs FOR CAAP FACILITIES
Implementation Notes
• Pilot plant studies are recommended, especially if units are to be used to
remove solids from stabilization pond effluents.
• When installing this technology in a facility, consider the characterization
of the suspended solids; the selection of unit design parameter values that
will provide adequate capacity to meet maximum hydraulic loadings with
critical solids characteristics; design parameters that also will provide
desired performance over the expected range of hydraulic and solids
loadings; and provision of backwash and cleaning facilities to maintain
the screen.
• Filters require cleaning to remove trapped particles. Sprayers are used to
remove collected particles and to provide additional filter cleaning. Filters
may also be cleaned using a periodic rinse cycle with a heated solution.
4.6 Secondary Settling with Vegetated Ditches
Systems: Ponds, flow-through, and redrculating
Vegetated ditches are another effective means of removing solids from effluent.
A vegetated ditch is an excavated ditch that serves as a discharge conveyance,
treatment, and storage system. The walls of the ditch are excavated at an angle
that supports the growth of a dense vegetation layer. The vegetation layer aids in
treating the discharge and reduces the susceptibility of the ditch banks and
bottom to erosion. The length and width of the ditch are designed to allow for
the slowing and temporary storage of the discharge as it flows toward the
receiving water body. The vegetation layer increases the ability of the ditch to
remove both coarse and fine particulate matter and the associated pollutants,
such as BOD, settleable solids, and suspended solids.
Vegetated ditches are channels lined with grass or other plants that can convey
or move water, treat discharges by removing sediment and solids, and store
water prior to discharge. The walls of a vegetated ditch are excavated at a slope
that allows for the growth of a dense vegetation layer, and the length and width
of the ditch are designed to slow the flow of the discharge.
Guidance
1. Ditches should be designed to convey the volume of wastewater
discharged with appropriate length and slope of ditch as well as suitable
vegetation to maximize pollutant removal.
2. Install riprap in bottoms of ditches in places that are susceptible to
erosion.
4-10
-------
SECTION 4: BMPs FOR CAAP FACILITIES
Implementation Notes
Vegetated ditches require regular maintenance. Maintenance practices include
the following:
• Repairs to ditch as needed.
• Weed and brush control to prevent competition with desirable species.
(mowing and herbicides)
• Irrigation during dry season to maintain vegetation.
• Routine inspection for repairs and after heavy rains.
4.7 Solids Polishing with Constructed Wetlands
Systems: Ponds, flow-through, and recirculating
Constructed wetland treatment systems also promote secondary solids removal
from effluent discharges. These systems consist of shallow pools constructed on
non-wetland sites. Constructed wetlands provide substrate for specific emergent
vegetation types such as cattail, bulrush, and reeds. Constructed wetlands are
designed to treat discharges through physical, chemical, and biological
processes. The vegetation causes the discharge to slow and flow in a more
serpentine manner, increasing the likelihood of solids settling. The vegetation
also aids in the adsorption of potential pollutants through plant and bacterial
uptake, and it increases the oxygen level in the discharge flowing through it.
Constructed wetland treatment systems consist of shallow pools constructed on
non-wetland sites with water at depths of usually less than 2 ft. They have
varying success in aquaculture operations. Constructed wetlands can be
designed to provide several different benefits, including treatment of the
discharge through biological and chemical processes, temporary storage of
discharges, recharge of aquifers, and reduction in discharge volume to receiving
water bodies.
Guidance
1. Site evaluation and selection. Consider site characteristics such as
topography, soil characteristics, existing land use, flood hazard, and
climate (Metcalf and Eddy, 1991).
2. Determination of pretreatment level. The minimum pretreatment for a
wetland system should be primary treatment or aerated ponds with a
short detention time. Use of oxidation ponds that generate high
concentrations of algae should be avoided prior to wetland treatment
because algae removal through wetlands is inconsistent. Phosphorus
4-11
-------
SECTION 4: BMPs FOR CAAP FACILITIES
removal prior to application to wetlands is recommended because
wetlands remove minimal phosphorus (Metcalf and Eddy, 1991).
3. Vegetation selection and management. Emergent plants, plants rooted in
the soil that penetrate the surface of the water, are used in constructed
wetlands. Constructed wetlands provide substrate for specific emergent
vegetation types such as cattail, bulrush, and sedges (Metcalf and Eddy,
1991).
4. Determination of design parameters. The primary design parameters for
constructed wetland systems are hydraulic detention time, basin depth,
basin geometry (width and length), 5-day biochemical oxygen demand
(BOD5), loading rate, and hydraulic loading rate (Metcalf and Eddy, 1991).
5. Vector control measures. Wetlands can provide breeding habitat for
mosquitoes; design plans might need to include measures for controlling
mosquitoes with mosquito fish or chemical control agents (Metcalf and
Eddy, 1991).
6. Detailed design of system components (Metcalf and Eddy, 1991).
7. Determination of monitoring requirements (Metcalf and Eddy, 1991).
Implementation Notes
• Once the system is operating properly, it should be inspected regularly to
remove dead or fallen vegetation, check for erosion and channelization,
and monitor sedimentation levels.
• Periodic harvest and proper disposal of the vegetation can also increase
nutrient removal.
• The wetlands require large areas for treatment of relatively small volumes
of water; therefore, facilities with limited available land for expansion are
not able to use constructed wetlands.
• In many parts of the United States, constructed wetlands have seasonal
differences in pollutant removal efficiencies. For example, in colder
climates, constructed wetlands might discharge some dissolved nutrients
during the colder season and become a sink for these pollutants during
warmer months.
4-12
-------
SECTION 4: BMPs FOR CAAP FACILITIES
4.8 Solids Disposal
Systems: Ponds, flow-through, recirculating, and alligators
4.8.1 Dewatering
Dewatering is the physical process used to reduce the moisture content of sludge to
make the sludge easier to handle before it is transported or composted. Several
techniques are used to dewater sludge. Some rely on natural evaporation, whereas
others use mechanically assisted physical means like filtration, squeezing, capillary
action, vacuum withdrawal, and centrifugal separation (Metcalf and Eddy, 1991).
Chemicals can be added to assist with the dewatering process.
Guidance
1. The selection of dewatering devices should be determined by the type of
sludge to be dewatered and the availability of space. Drying beds or
lagoons can be used where land availability is not an issue. Mechanical
devices are more likely to be used on sites where space is restricted.
2. Some sludges, such as aerobically digested sludges, do not respond well
to mechanical dewatering.
4.8.2 Composting
Composting is a process in which organic material undergoes biological
degradation to a stable end product (Metcalf and Eddy, 1991). Approximately 20%
to 30% of the volatile solids are converted to carbon dioxide and water. As the
organic material in the sludge decomposes, the compost heats to temperatures in
the range of 120 to 160 °F, and pathogenic organisms are destroyed.
Guidance
Composting generally involves the following steps:
1. Mixing dewatered sludge with an amendment or bulking agent. Fish
manure is usually dense, wet, and nitrogen-rich; therefore, it is necessary
to mix the manure with materials like straw, corn stalks, yard trimmings,
or wood chips to add carbon and absorb excess moisture.
2. Aerating the compost pile by adding air or mechanically turning the
compost.
3. Recovery of the bulking agent.
4. Further curing and storage.
5. Final disposal.
4-13
-------
SECTION 4: BMPs FOR CAAP FACILITIES
4.8.3 Land Application
Land application is the most common sludge disposal process in the aquaculture
industry (Chen, 2002). Land application of sludge is defined as the spreading of
sludge on or just below the soil surface (Metcalf and Eddy, 1991). Application
methods include using sprinklers and tank trucks to apply the sludge directly to
the land. Sludge may be applied to agricultural land, forest land, disturbed land,
and dedicated land disposal sites. In all of these cases, the land application is
designed with the objective of further providing sludge treatment (Metcalf and
Eddy, 1991). Sunlight, soil microorganisms, and dryness combine to destroy
pathogens and other toxic organic substances found in sludge.
Guidance
Sprinkler application
1. When agricultural land is adjacent to an AAP facility, solids can be
vacuumed directly from quiescent zones and into a sprinkler system that
applies solids and water.
2. Application rates should not cause surface runoff or contaminate
groundwater.
3. The sprinkler line should have a small settling pond at the end of the line
to allow for emergency cleaning during freezing weather.
Field application
1. For use of slurry on fields, consider site conditions (weather), timing of
application, application rates, crop type, crop uptake capacity, and land
availability (IDEQ, n.d.)
2. Consider the slope of the field and the location of surface water to prevent
slurry from entering surface waters during or after application.
3. Avoid field areas with exposed bedrock or shallow soil because nutrients
might leach into the groundwater.
4. Plan ahead and maintain good working relationships with nearby farmers
to find fallow fields during the growing season and accessible fields
during the winter months.
4.8.4 Publicly Owned Treatment Works
Publicly owned treatment works (POTWs) are wastewater treatment plants that
are constructed and owned by a municipal government for the purpose of
treating municipal and industrial wastewater from homes and businesses within
4-14
-------
SECTION 4: BMPs FOR CAAP FACILITIES
its borders and/or surrounding areas. Facilities that discharge to POTWs are
considered to be indirect dischargers because their wastewater is directed to a
POTW for treatment before being discharged to surface water. Some aquaculture
facilities are indirect discharges.
4.8.5 Storage Tanks and Lagoons
Manure, or sludge, from aquaculture facilities has to be properly treated and
disposed. Storage tanks or storage lagoons are used to store either untreated or
treated wastewater until the water can be treated, or until the treated wastewater
can be reused by the production system. Holding tanks, storage tanks, and surge
tanks are used through the aquaculture industry to hold wastewater and treated
wastewater before they are returned to the culture system.
Guidance
1. Storage lagoons are usually shallow, bermed earthen ponds with a high
surface area-to-volume ratio to facilitate rapid drying of slurry. For
example, a lagoon with dimensions of 300 ft by 50 ft and a depth of 1 ft is
needed to store 120,000 gal (IDEQ, n.d.)
2. To avoid nutrient leaching, facilities should avoid building storage
lagoons on or near exposed bedrock, on thin or sandy soil, or in locations
with high groundwater.
3. Storage lagoons should be sited away from natural drainage areas prone
to flooding.
4.9 Active Feed Monitoring
System: Net pens
In addition to general feed management, feed management practices for net pen
facilities should include a real-time monitoring system to monitor the rate of feed
consumption. Excess feed is the primary source of sediment accumulation
beneath net pens, which can have an adverse effect on the benthic community.
Active feed monitoring is considered a management practice for all net pen
facilities. This relatively new but proven technology is used by some facility
operators in the salmon industry. Some type of remote monitoring equipment,
such as an underwater video camera, is lowered from the surface to the bottom
of a net pen during feeding to monitor for uneaten feed pellets as they pass by
the camera.
The goal of active feed monitoring is to further reduce pollutant loads associated
with feeding activities. Various technologies have been reported, including video
cameras with human or computer interfaces to detect passing feed pellets. A new
4-15
-------
SECTION 4: BMPs FOR CAAP FACILITIES
NPDES permit issued in Maine (USEPA, 2002) also suggests that ultrasonic
equipment might be available. Most facilities that use this technology use a video
monitor at the surface that is connected to the video camera. An employee
watches the monitor for feed pellets passing by the video camera and then stops
feeding activity when a predetermined number of pellets (typically only two or
three) pass the camera.
4.10 Practices to Minimize the Potential Escape of Nonnative Species
Systems: Ponds, flow-through, recirculating, and net pens
Practices to minimize the potential escape of nonnative species are designed to
prevent nonnative aquatic organisms from escaping and adversely affecting local
wild populations. These practices might include precautions such as double
netting for net pen systems or screens over influent and effluent drains for flow-
through systems. Practices might also include protocols for escape recovery and
steps taken to prevent fish from escaping during stocking and grading activities.
Guidance
1. Describe the precautions the facility will take to prevent nonnative aquatic
organisms from escaping and adversely affecting local wild populations.
a. Describe in detail the precautions the facility will take to minimize the
potential escape of nonnative species.
b. Include a description of a schedule for preventative maintenance and
inspection of the containment system, methods of escape recovery
protocols, and fish transfer procedures during stocking and grading.
2. For net pen systems, describe secondary containment equipment.
Secondary containment involves the use of a second set of containment
netting around a net pen system. The secondary containment netting
should be positioned to capture any fish that might escape the primary
containment netting because of damage to the net pen system that could
occur during a storm event or other structural failure.
4.11 Mortality Removal
Systems: Ponds, flow-through, recirculating, and net pens
Mortality of the cultured species in small numbers is a common occurrence in
aquaculture systems. The timely removal of mortalities ensures against the
spread of disease and the introduction of excess nutrients into the system. There
are no known disadvantages to the timely removal of mortalities; however, when
ponds have large numbers of mortalities, removal might be costly and require
seines and crews similar to those used during harvest.
4-16
-------
SECTION 4: BMPs FOR CAAP FACILITIES
Guidance
1. Maintain good water quality to prevent disease outbreaks.
2. Avoid overstocking rearing units to reduce stress and promote optimal
culture water quality.
3. Inspect culture units daily to check for the presence of mortalities.
4. Many of the mortalities float to the surface of the culture water and can be
collected by hand or with nets.
4.12 Net pen siting
System: Net pens
Siting involves the preimplementation planning that should take place to ensure
that the net pen system is located in an area of adequate flow. Net pens located in
areas without sufficient tidal flow have an increased probability of solids
buildup below the pens. The net pens should also be located in areas that are
protected from storm events so they do not become a hazard to navigation.
Guidance
1. Evaluate prospective sites to determine flushing rates, as well as the
direction in which waste products will be carried as a function of tidal
flow and wind generation (Stickney, 2002).
2. Identify any physical conditions, such as water depth, that may affect
dispersal of nutrients
3. Consider establishing operations in suitable offshore environments to
reduce nearshore environmental impacts.
4. Consider sites that can be used for polyculture as a means of reducing
nutrient accumulations beneath the net pens (Stickney, 2002).
5. Consider rotating pen locations, if possible, to minimize impacts on
benthic communities.
4.13 Net cleaning
System: Net pens
The regular cleaning of the production nets helps to ensure a constant flow of
water through the production area of the net pen. As the net pen sits in the
culture area, marine organisms attach and grow on the nets. These organisms
reduce the area of the openings. The reduction in area reduces the water flow
4-17
-------
SECTION 4: BMPs FOR CAAP FACILITIES
through the net pen and the amount of dissolved oxygen available, and it
increases the buildup of metabolic waste.
Guidance
1. Minimize the concentration of net-fouling organisms that are discharged
during events such as changing and cleaning nets.
2. Remove fouled nets, transport ashore, air dry, and clean with pressure
washers, if necessary. Avoid discharges of cleaning water or net-fouling
organisms to open waters.
3. Avoid discharges of chemicals used to clean nets or other gear in open
waters.
4. Do not use materials containing or treated with tributylin.
4.14 Discharge Management
System: Ponds
Ponds can release effluents through overflow from rain events and intentional
draining. Effluent volume can be reduced by operating ponds to maximize
storage capacity to reduce overflow and by draining ponds only when necessary.
Discharge management applies practices to reduce the volume of water discharged
and to improve the quality of the effluent discharged.
Water might be intentionally discharged from ponds to facilitate harvests or to
improve the quality of the water in the pond by flushing or exchanging the water
with new water additions. For catfish ponds, draining might occur any time
during the year. Scheduling drainings, when possible, to minimize the release of
sediment and nutrients can reduce the potential pollutants in pond effluent. The
following summary is based on guidance from Alabama Aquaculture BMP
Practice No. 10, "Managing Ponds to Improve Quality of Draining Effluent"
(Auburn University and USD A, 2002J).
Guidance
1. When possible, construct seine-through ponds that do not have to be
drained for harvest.
2. Harvest fish by seining and without partially or completely draining the
pond unless it is necessary to harvest in deep ponds, restock, or repair
pond earthwork. Where possible, avoid discharge when harvesting fish.
3. Avoid flushing new supplies of water into the pond by discharging a
portion of the production water. Research has proven that mechanical
4-18
-------
SECTION 4: BMPs FOR CAAP FACILITIES
aeration is a more effective mean of preventing low dissolved oxygen
levels than the practice of water exchange.
4. Discharge due to rainfall events can be prevented by maintaining the
water level below the tops of the overflow pipes. When makeup water is
added, it should be kept 3 to 4 in. below the tops of overflow pipes,
preventing storm overflow. Pond edges can be deepened if water becomes
shallow around the edges.
5. Design new ponds with structures that allow the ponds to be drained near
the surface instead of from the bottom. Where practical, alter drain
structures for surface discharge when old ponds are drained for harvest or
renovation.
6. Typically ponds must be drained completely to repair the pond and the
surrounding area. The frequency of draining varies from every few years
up to every 20 years. When ponds must be drained completely, it is
recommended that the final 20% to 25% of the pond volume be discharged
into a settling basin or held for 2 or 3 days to minimize suspended solids
and then discharged slowly.
7. When draining ponds, drain from the surface to the bottom. If necessary,
swivel-type drains can be installed to take in water from the surface and
be lowered to completely drain the pond. Most catfish pond drains
usually have the discharge pipe inlet at the pond bottom.
8. Use riprap at discharge points to protect against erosion.
Implementation Notes
• During final draining the valve should be opened to one-fourth its
maximum capacity. At the beginning of rainfall the valve should be closed
and not reopened until the water has cleared.
• Where ponds are located in close proximity, water from the pond being
drained for harvest can be transferred to adjacent ponds for reuse.
4.15 Erosion Control
System: Ponds
Erosion occurs in ponds as a result of wave action, water currents from aerators,
inadvertent damage from vehicles and other farm equipment, and rain affecting
bottoms, dams and embankments of empty ponds (Auburn University and
USD A, 2002d; Auburn University and USD A, 2002e). Soil particles suspended by
erosion increase TSS concentrations in pond waters and effluents, and clay
particles increase turbidity. Sediment that has been removed from ponds but
4-19
-------
SECTION 4: BMPs FOR CAAP FACILITIES
improperly disposed of can erode and cause contamination of surface water with
suspended solids.
Erosion can also occur within the pond watershed, on the sides and tops of pond
embankments, in emergency spillways, and from farm roads around the pond,
access roads to the farm, and stream crossings. These sources of sediment
increase suspended solids concentrations and turbidity in pond waters. Erosion
control minimizes the input of solids added to pond waters and also reduces the
levels of suspended solids in pond effluents.
In the pond, wave action against embankments causes soil particles to detach.
Grass cover above the normal water level on the wet side of embankments
provides protection from wave action. Erosion is most severe when water levels
are low and bare soil is exposed to waves and rain. Aerators can also increase
erosion by generating strong water currents that can suspend soil particles from
the pond bottoms and detach soil particles from pond banks. Sediment
accumulates in ponds over time and eventually needs to be removed. If sediment
is placed in unvegetated piles, rain falling on the piles causes erosion and the
runoff has high concentrations of suspended solids.
In the pond watershed, erosion from soil surfaces can result from rain events that
loosen soil particles. Runoff flowing downslope can suspend and transport the
loose particles. The energy of flowing water can result in gullies. Bare soil
exposed on farm roads or the tops of embankments erodes easily; erosion
potential also increases with a steeper slope. In addition, livestock traffic can also
expose bare soil or create paths that are highly erodible. If cattle wade in ponds,
they suspend sediment and increase turbidity.
The following guidance is based on Alabama Aquaculture BMP No. 3, "Erosion
Control on Watershed and Pond Embankments;" No. 4, "Pond Management to
Minimize Erosion," and No. 5, "Control of Erosion by Eflluents" (Auburn
University and USD A, 2002c; Auburn University and USDA, 2002d; Auburn
University and USDA, 2002e).
Guidance
1. Close drains as soon as the maintenance or other activities for which the
pond was drained are completed.
2. If possible, prevent damage to levees or embankments caused by
equipment or vehicles. If damage does occur, make repairs immediately to
prevent erosion.
3. Install stationary mechanical aerators such that water currents caused by
these devices do not cause erosion of pond banks or bottoms.
4-20
-------
SECTION 4: BMPs FOR CAAP FACILITIES
4. Position tractor-powered emergency aerators to avoid erosion.
5. Sediment should be used where possible to repair pond earthwork. If
sediment is removed from ponds, it should be stabilized to prevent
erosion.
6. Use earthen berms, riprap, or vegetation to minimize erosion from wave
action in the pond.
7. Control erosion in watersheds by providing vegetative cover, eliminating
gully erosion, and using diversions to route water away from areas of
high erosion potential.
8. Eliminate steep slopes on farm roads and cover these roads with gravel,
especially roads built on soil with high clay content.
9. Use a 3:1 (horizontal:vertical) ratio or flatter side slopes for pond
embankments in new construction.
10. Provide grass cover on the sides of pond dams or embankments and grass
or gravel on the tops of dams or embankments.
11. NRCS recommends that new ponds or extensions of existing ponds
should be constructed to maintain 40% to 50% of the owner's 100-year
floodplain area near the channel.
Implementation Notes
• For watershed ponds, enough watershed area to supply water to fill
ponds during the winter and spring is desirable; however, excessive
overflow from ponds could cause erosion of pond outlet structures and
increase TSS in effluents.
• Diversions can be useful for controlling water in the watershed. A
diversion is a channel constructed across the slope with a supporting
ridge on the lower side.
• Maintain storage between the top of the overflow pipe (approximately 3
to 4 in.) and the surface of the water.
• Water overflowing out of ponds also flushes out products added to ponds
to enhance water quality and fish production (e.g., fertilizer, lime, salt);
therefore, overflow discharges can waste resources and affect fish
production.
4-21
-------
SECTION 4: BMPs FOR CAAP FACILITIES
4.16 Managing Rainwater and Reducing Overflow
System: Ponds
Rainwater management includes practices that minimize overflows from ponds
during rain events. Storm runoff or overland runoff is the water that flows over
the land surface following rainfall events. The amount of water entering ponds
depends on the size and characteristics of the watershed and the intensity of the
storm event. Rainwater management practices are influenced by the pond type,
levee or watershed. Moreover, the volume of effluent from ponds in response to
heavy rains depends on the watershed area-to-pond surface ratio.
There are two common types of pond discharge: release of effluents following
rainfall events and intentional draining for harvest or repair of the ponds.
Effluent volume can be reduced by operating ponds to maximize storage
capacity and draining them only when necessary.
Discharge from a pond due to overflow after a rain or storm event occurs when
the amount of water entering the pond exceeds the capacity of the pond to store
water. Discharge due to overflow can be mostly avoided if the pond is not full to
the top of the overflow pipes when rain occurs. When overflows do occur, the
impact of potential effluents can be minimized by maintaining good water
quality in the pond system by using aeration. The following guidance is based on
Alabama Aquaculture BMP No. 9, "Managing Ponds to Improve Quality of
Overflow Effluent," and BMP No. 2, "Managing Ponds to Reduce Effluent
Volume"(Auburn University and USD A, 2002b; Auburn University and
USD A, 2002i).
Guidance
1. Maintain adequate storage capacity to capture rain falling or running into
ponds during summer and early fall by maintaining the water level below
the top of the stand pipe drain.
2. Use diversions or grade stabilization structures to divert excess runoff
around ponds, or, if possible, build an additional pond to increase water
storage capacity.
3. Maintain good vegetative cover on all parts of the watershed. Where
possible, replace short or sparse vegetation with taller, denser vegetation.
4. Improve the quality of the overflow by maintaining adequate dissolved
oxygen levels using mechanical aeration.
5. Avoid the practice of rearing livestock on farm watershed and allowing
livestock to walk on pond embankments and near ponds. Livestock
4-22
-------
SECTION 4: BMPs FOR CAAP FACILITIES
produce manure that may wash into the ponds and degrade the quality of
the water by adding additional nutrients.
Implementation Notes
• For watershed ponds, enough watershed area to supply water to fill
ponds during the winter and spring is desirable; however, excessive
overflow from ponds can cause erosion of pond outlet structures and
increase total suspended solids in effluents.
• Diversions can be useful for controlling water in the watershed. A
diversion is a channel constructed across the sloping landscape with a
supporting ridge on the lower side.
• Maintain storage between the top of the overflow pipe (approximately 3
to 4 in) and the surface of the water.
• Water overflowing out of ponds also flushes out products added to ponds
to enhance water quality and fish production (e.g., fertilizer, lime, salt);
therefore, overflow discharges can waste resources and affect fish
production.
4.17 Using Drugs and Chemicals: Fertilizers, Therapeutic Agents, and Water
Quality Enhancers for Ponds
System: Ponds
Guidance for pond systems
1. For pond systems, apply fertilizers only when necessary to promote
phytoplankton blooms (Auburn University and USDA, 2002h).
2. Use Secchi disk visibility to determine if fertilizer is necessary (Auburn
University and USDA, 2002h).
3. Manage pond water levels to prevent or minimize effluent release if
possible (Auburn University and USDA, 2002h).
4. Apply agricultural limestone to ponds with a total alkalinity below
20 ppm (Auburn University and USDA, 2002h).
5. Only use water quality enhancers that have been approved by FDA and
EPA, and follow the label instructions carefully (Auburn University and
USDA, 20021).
4-23
-------
SECTION 4: BMPs FOR CAAP FACILITIES
4.18 Oxidation Lagoons
Systems: Flow-through, recirculating, and alligator
Oxidation lagoons, also know as stabilization ponds, are usually earthen,
relatively shallow wastewater treatment units used to separate solids and treat
soluble organic wastes (Metcalf and Eddy, 1991). The basins are cleaned of solids
as needed, which might be as long as once every 20 years. Oxidation ponds are
used extensively in the wastewater treatment industry and are commonly used
by the alligator industry for the treatment of wastewater generated during
alligator pen cleaning.
Oxidation lagoons are usually classified as aerobic, anaerobic, or aerobic-
anaerobic (facultative) according to the nature of the biological activity in the
pond. Aerobic and facultative lagoons require that oxygen be added to all or
parts of the lagoon constantly; therefore, in order to reduce costs, most lagoons in
the alligator industry are operated as anaerobic lagoons.
4.19 References
Auburn University and U.S. Department of Agriculture (USDA). 2002a. Alabama
Aquaculture BMP fact sheets, No. 1: Reducing Storm Runoff into Ponds.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002b. Alabama
Aquaculture BMP fact sheets, No. 2: Managing Ponds to Reduce Effluent
Volume.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002c. Alabama
Aquaculture BMP fact sheets, No. 3: Erosion Control on Watershed and
Pond Embankments.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002d. Alabama
Aquaculture BMP fact sheets, No. 4: Pond Management to Minimize
Erosion.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002e. Alabama
Aquaculture BMP fact sheets, No. 5: Control of Erosion by Effluents.
4-24
-------
SECTION 4: BMPs FOR CAAP FACILITIES
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002f. Alabama
Aquaculture BMP fact sheets, No. 6: Settling Basins and Wetlands.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002g. Alabama
Aquaculture BMP fact sheets, No. 7: Feed Management.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002h. Alabama
Aquaculture BMP fact sheets, No. 8: Pond Fertilization.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 20021. Alabama
Aquaculture BMP fact sheets, No. 9: Managing Ponds to Improve Quality
of Overflow Effluent.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002]. Alabama
Aquaculture BMP fact sheets, No. 10: Managing Ponds to Improve Quality
of Draining Effluent.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002k. Alabama
Aquaculture BMP fact sheets, No. 11: Therapeutic Agents.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 20021. Alabama
Aquaculture BMP fact sheets, No. 12: Water Quality Enhancers.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002m.
Alabama Aquaculture BMP fact sheets, No. 13: Fish Mortality
Management.
.
Accessed May 23, 2002.
4-25
-------
SECTION 4: BMPs FOR CAAP FACILITIES
Auburn University and U.S. Department of Agriculture (USDA). 2002n. Alabama
Aquaculture BMP fact sheets, No. 14: General Operations and Worker
Safety.
.
Accessed May 23, 2002.
Auburn University and U.S. Department of Agriculture (USDA). 2002o. Alabama
Aquaculture BMP fact sheets, No. 15: Emergency Response and
Management.
.
Accessed May 23, 2002.
Chen, S., S. Summerfelt, T. Losordo, and R. Malone. 2002. Recirculating systems,
effluents and treatments. In Aquaculture and the Environment in the United
States, ed. J.R. Tomasso, pp. 77-104. U.S. Aquaculture Society,
Baton Rouge, LA.
IDEQ (Idaho Division of Environmental Quality). N.d. Waste Management
Guidelines for Aquaculture Operations. Idaho Division of Environmental
Quality, Boise, ID
Metcalf and Eddy, Inc. 1991. Wastewater Engineering: Treatment, Disposal, and
Reuse, Third edition, McGraw Hill, New York, New York.
Stickney, R.R. 2002. Impacts of cage and net-pen culture on water quality and
benthic communities. In Aquaculture and the Environment in the United
States, ed. J.R. Tomasso pp. 105-118. U.S. Aquaculture Society,
Baton Rouge, LA.
Tucker, C.S., Mississippi State University. 2001. Personal communication,
November 19, 2001.
USEPA (U.S. Environmental Protection Agency). 2002. NPDES Permit no.
ME0036234. Issued by USEPA Region 1 to Acadia Aquaculture, Inc.
Signed February 21, 2002.
4-26
-------
APPENDIX A
ADDITIONAL RESOURCES
-------
-------
APPENDIX A: ADDITIONAL RESOURCES
Pond systems
Auburn University and U.S. Department of Agriculture (USDA). 2002. Alabama
Aquaculture BMP fact sheets, No. 1-15.
.
Accessed May 23, 2002.
Boyd, C.E. 1981. Fertilization of warm water fish ponds. Journal of Soil and Water
Conservation 36:112-142.
Boyd, C.E. 1982. Liming fish ponds. Journal of Soil and Water Conservation
37:86-88.
Boyd, C.E. 1982. Hydrology of small experimental fish ponds at Auburn,
Alabama. Transactions of the American Fisheries Society 111:638-641.
Boyd, C.E. 1998. Pond water aeration systems. Aquacultural Engineering 18: 9-40.
Boyd, C.E. 1999. Codes of Practice for Responsible Shrimp Farming. Global
Aquaculture Alliance, St. Louis, MO.
Boyd, C.E., and T. Dhendup. 1995. Quality of potential effluents from the
hypolimnia of watershed ponds used in aquaculture. Progressive Fish-
Culturist 57:59-63
Boyd, C.E., and C.S. Tucker. 1998. Pond Aquaculture Water Quality Management.
Kluwer Academic Publishers, Boston, MA.
Boyd, C.E., P. Munsiri, and B.F. Hajek. 1994. Composition of sediment from
intensive shrimp ponds in Thailand. World Aquaculture 25: 53-55.
Browson, M.W. 1996. Catfish Quality Assurance. Publication no. 1873. Mississippi
Cooperative Extension Service.
Hollerman, W.D., and C.E. Boyd. 1985. Effects of annual draining on water
quality and production of channel catfish in ponds. Aquaculture 46:45-54
McGee, M.V., and C.E. Boyd. 1983. Evaluation of the influences of water
exchange in channel catfish ponds. Transactions of the American Fisheries
Society 112:557-560.
Schwartz, M., and C.E. Boyd. 1994. Effluent quality during harvest of channel
catfish from watershed ponds. Progressive Fish-Culturist 56:25-32
A-l
-------
APPENDIX A: ADDITIONAL RESOURCES
Seok, K., S. Leonard, C. E. Boyd, and M. Schwartz. 1995. Water quality in
annually drained and undrained channel catfish ponds over three-year
period. Progressive Fish-Culturist 57: 52-58.
USDA (U.S. Department of Agriculture). 1977. U.S. Department of Agriculture,
National Resources Conservation Service (NRCS). Conservation Practice
Standard, Channel Vegetation. Revised January 1989.
USEPA. 1996. Protecting Natural Wetlands: A Guide to Stormwater Best Management
Practices. EPA-843-B-96-001, USEPA, Office of Water, Washington, DC.
Wellborn, T.L. n.d. Catfish Farmer's Handbook. Mississippi Cooperative Extension
Service, Mississippi State University.
Yoo, K.H. and C.E. Boyd. 1994. Hydrology and Water Supply for Pond Aquaculture.
Chapman and Hall, New York, New York.
Flow-through systems
IDEQ (Idaho Division of Environmental Quality), n.d. Waste Management
Guidelines for Aquaculture Operations. Boise, ID.
.
Accessed September 2001.
USTFA (U.S. Trout Farmer's Association). 1994. Trout Producer Quality Assurance
Program. U.S. Trout Farmer's Association. Charles Town, WV.
Recirculating systems
Summerfelt, S.T. and B.J. Vinci. 2002. Best waste management practices for
coldwater recirculating systems. In Proceedings of the Fourth International
Conference on Recirculating Aquaculuture, ed. T.T. Rakestraw, L.S Douglas,
and G.J. Flick, Roanoke, Virginia, July 18-21, 2002.
General
ABOFGA (Arkansas Bait and Ornamental Fish Growers Association). N.d. Best
Management Practices (BMP's)for Baitfish and Ornamental Fish Farms.
Arkansas Bait and Ornamental Fish Growers Association, in cooperation
with the University of Arkansas at Pine Bluff, Aquaculture/Fisheries
Center.
FDACS (Florida Department of Agriculture and Consumer Services). 2000.
Aquaculture Best Management Practices. Florida Department of Agriculture
and Consumer Services, Division of Aquaculture, Tallahassee, FL.
A-2
-------
APPENDIX A: ADDITIONAL RESOURCES
Fitzsimmons, K. 1999. Draft: Arizona Aquaculture BMPs. Arizona Department of
Environmental Quality, .
Accessed September 25,2001.
Howerton, R. 2001. Best Management Practices for Hawaiian Aquaculture.
Publication No. 148. Center for Tropical and Subtropical Aquaculture,
University of Hawaii Sea Grant Extension Services. Honolulu, HI.
LSU (Louisiana State University). 1999. Draft Louisiana Best Management Practices
(BMPs) for Aquaculture. Louisiana State University, Agricultural Center.
Metcalf and Eddy, Inc. 1991. Wastewater Engineering: Treatment, Disposal, and
Reuse. 3rd edition. Metcalf and Eddy, Inc., New York, NY.
Swann, L. 1997. A Fish Farmer's Guide to Understanding Water Quality. Sea Grant
no. IL-IN-SG-97-2. Illinois Sea Grant Program, Aquaculture Extension.
A-3
-------
-------
APPENDIX B
EXAMPLE BMP PLAN
-------
-------
APPENDIX B: EXAMPLE BMP PLAN
Example BMP Plan1
FantaSea Fish Farm
Prepared October 6,2000
for EPA NPDES Workshop
held November 8, 2000
Goal: To describe the standard operating procedures and best management
practices used to minimize, collect, and dispose of pollutants generated during
facility operations.
Description: FantaSea Fish Farm is a Class 3 aquaculture facility that produces
approximately 250,000 Ibs of rainbow trout annually. The facility was initially
constructed in 1962. The facility expanded to include a third use of raceways and
an off-line settling pond system in 1987. The facility presently has 12 100 fit long
raceways, a small hatchery building, an off ice/shop, and an OLS pond for waste
treatment (see attached diagram). The fish farm is located near Jerome, Idaho
(T_, R_, Sec_). The facility has a non-consumptive water right for 14 cfs of water
from Ideal Springs. The facility has two discharge points, both of which go into
Ideal Creek. FantaSea Fish Farm's NPDES permit number is IDG130000. The
facility was covered under the Idaho General Permit for Aquaculture Facilities
March 1, 2000. FantaSea Fish Farm's previous NPDES permit number was
IDOOOOOO-0.
Source: The FantaSea Farm uses water that comes from Ideal Spring. Ideal Spring
is a pure spring source with TSS levels generally measured at less than 2.0 mg/L
(see historic DMRs). Aquatic vegetation grows in the spring and the ditch
leading to the raceways. An inflow trash rack screen is used to catch vegetation
from the springs and ditch prior to entering the facility. The trash rack screen is
cleaned at least daily to prevent vegetation from affecting the water flow to the
facility. The spring and head ditch is manually cleaned twice a year to prevent
build up of aquatic vegetation. The ditch has an adjustable head gate that
controls the water flow to the facility from the spring area.
Influent weir: FantaSea Farm uses an influent weir to measure flow for the
facility. Their weir is a calibrated suppressed rectangular weir. The weir is
located below the trash rack screen to prevent debris from interfering with weir
measurements. The weir is checked for level annually. The weir face and box
area is swept clean prior to any measurements being taken. The staff gauge is
placed along the weir box wall six times the head distance upstream of the weir
crest. The weir has a 3/16 in. blade crest that falls off to a 45° angle to allow
1 Prepared by Rob Sharpnack, DEQ and Carla Fromm, USEPA
B-l
-------
APPENDIX B: EXAMPLE BMP PLAN
water to spring free of the blade. If the blade is nicked, bent, or rounded it is to
be replaced. Weir calibration and testing curve validation is conducted annually.
Immediately below the catch pool for the weir is the influent fish screen used to
prevent fish from swimming out of the rearing areas and into the springs.
Raceways: At the bottom of each raceway is a 20 ft. long quiescent zone (QZ).
The QZ distance meets the minimum desing criteria set forth by the State of
Idaho in the Idaho Waste Management Guidelines for Aquaculture Operations for QZ
length. Each QZ has a wastewater drain line connection that allows each QZ to
be vacuumed individually. The vacuum hose is attached to slotted pipe that is 2
ft. long that serves a vacuum head. Floats are attached to the vacuum hose to
prevent the hose from stirring up solids during cleaning events. Gravity
transports the wastewater from the QZ to the OLS pond for treatment and
storage.
The delivery rate of wastewater to the OLS pond for raceway or QZ cleaning is
200 gpm. The delivery rate for the OLS system is the average time it takes to fill a
known volume (the empty OLS pond). QZ cleaning is done sporadically
throughout the work week.
Quiescent zones are vacuumed every two weeks and prior to fish grading or
harvesting events. The screens in front of the QZ are cleaned daily to removr
moss and dead fish. Screens are cleaned to facilitate settling of biosolids from the
raceway and to prevent blowouts.
The purpose of the QZ area is to settle out biosolids for easy collection and rapid
removal from the rearing environment to prevent their discharge from the
facility. Fish that get into the QZs are removed promptly when discovered.
The raceways are screened to prevent avian predators from eating the fish. This
benefits the waste management on the farm by reducing direct mortality from
injured fish. The netting reduces indirect mortality by reducing the incidence of
disease on the facility. Healthy fish consume feed better, which prevents uneaten
feed from going to waste. Also, healthy fish are more active in the raceway which
allows accumulated biosolids to be moved more readily down the raceway to the
QZs, facilitating cleaning and faster removal of biosolids.
Raceways above the QZ are vacuumed before any scheduled fish grading or
harvesting events to prevent unnecessary disturbance and subsequent discharge
of biosolids from the raceways.
The level of the roadways around the raceways has been graded down to be
approximately 1 ft below the level of the raceway walls. This prevents
B-2
-------
APPENDIX B: EXAMPLE BMP PLAN
stormwater and windblown dirt from entering the raceways and adding to the
waste management load for the facility.
There is approximately 2.5 ft of drop between the first and second use of
raceways to allow for passive oxygen recharge of the raceway water. There is 3.5
ft of drop between the second and third raceway use. Between raceway sections
the waterfalls onto a splashboard before entering the next lower section. The
purpose of this splashboard is to break up the water stream leaving the upper
raceway and expose as much surface area of the water to open air as possible to
maximize the replenishment of dissolved oxygen levels in the raceway waters.
After the third and final use, water falls 3.5 ft to a concrete pad before flowing
into the tail ditch and off of the facility. We feel that the accomplishes the same
goal as the splashboards between raceway sets (i.e. it maximizes DO levels for
wastewater entering Ideal Creek).
Influent and effluent settleable solids from the raceways has always been < 0.1
ml/L. Net TSS results have been between 1.0 mg/L and 4.0 mg/L. Facility flow
fluctuates through the year and ranges form 12 to 14 cfs. In 1990-91, six
phosphorus and nitrogen samples were taken from the raceway influent and
effluent. Net phosphorus results for the raceways averaged 0.07 mg/L. Net
nitrite + nitrate results were 0.02 mg/L. Net TKN results were 0.3 mg/L. Net
ammonia results were 0.2 mg/L.
OLS Pond: The OLS pond is set up to handle a design flow of 300 gpm. The
dimensions of the OLS pond are 30 ft by 30 ft (surface area of 900 sq ft). The pond
slopes to a maximum depth of 3.5 ft. Wastewater comes into the OLS pond from
the gravity flow system pipe that spills onto the access ramp. This helps to
distribute the flow across the width of the settling pond. Water leaves the pond
through an 8 in. standpipe. The standpipe is attached to a 90° elbow that can
swivel inside the pond. There is a collar around the standpipe that causes the
water that is discharged to be pulled from 20 in. below the pond surface. The
collar prevents floating materials from washing out of the pond. The water
leaving the pond goes back to a box with a calibrated v-notched weir. The weir is
used to verify flow rates through the OLS pond during cleaning events.
When the OLS pond is harvested, the water in the pond is slowly decanted by
removing the collar from around the standpipe and slowing rotating the
standpipe on the 90° elbow to gradually lower the water level in the pond. Once
the pond is decanted, a tractor is driven into the pond and the slurry is stirred to
a uniform consistency to allow for pumping. The sludge is pumped from the
OLS pond into a "honey wagon" which takes it a field for land application.
Solids content of the slurry varies between 6 % and 12 %.
The OLS pond is harvested twice annually. (Spring and Fall)
B-3
-------
APPENDIX B: EXAMPLE BMP PLAN
Effluent settleable solids results for the OLS pond has always been <1.0 ml/L.
Gross TSS results have ranged from 20 mg/L to 87 mg/L. Monthly average flows
for the OLS pond have historically ranged from 0.01 mgd to 0.03 mgd. In 1990-
1991, six phosphorus and nitrogen samples were taken from the OLS pond
influent and effluent. Gross phosphorus results for the OLS pond averaged 3.2
mg/L. Net nitrite + nitrate results were 0.62 mg/L. Net TKN results were 5.3
mg/L. Net ammonia results were 1.8 mg/L.
Feeding: FantaSea Fish Farm recognizes that the fish feed management is critical
in operating an environmentally friendly and profitable fish farm.
Approximately 250,000 Ib of trout are produced per year on about 300,000 Ib of
feed, at a conversion rate of 1.2. Feed used is produced from Best Feed for Fish
and generally is composed of % ash, % phosphorus, and 30% fat. Feed
contents do change based on availability of constituents to the feed
manufacturer. FantaSea uses commercially available sinking extruded diets to
feed our fish. We fee that using extruded diets leads to the best feed conversion
ratios and this minimizes the amount of waste generated by the facility. Specific
quantities of feed are fed through demand feeders on each outdoor raceway
depending on the quantity, size, and condition of the fish in that raceway. There
are two demand feeders on each raceway. Demand feeders allow the fish to
decide how much food they need and when they want to feed. This maximizes
feeding opportunity and lowers feed conversions by providing a steady, stress
free, feeding environment with little wastage. Demand feeders are filled daily or
as necessary. Fish in the hatchery building are fed by hand several times per day.
Bagged feeds are stored in the shop area and are used on a "first in, first out"
basis to prevent lengthy storage of feed. Use of fresh diets improves dietary
efficiency. No feed is used if it has exceeded the storage period recommended by
the manufacturer. The largest diets are purchased in bulk and stored in feed bins.
Feed can be poured from the bins and fines screened off before the feed is put in
the demand feeders.
Demand feeders need to be constantly adjusted to the conditions on the facility
to maximize feeding efficacy. Any feeder discovered to be out of adjustment
(feeding too freely or jammed up) is immediately corrected by an employee.
Employees are to observe the feeding behavior of the fish at all times. Fish that
are not feeding well should have their feed restricted until they are again feeding
normally to prevent feed from being wasted and discharged.
All the demand feeders are set up with a windshield to prevent the undesired
release of feed on windy days.
Fish are taken off feed prior to harvest, movement or grading to minimize
mortality that can occur from those activities.
B-4
-------
APPENDIX B: EXAMPLE BMP PLAN
Hatchery Building: The hatchery building is where trout eggs are hatched and
the fish raised up to a size where they can be moved outdoors to the production
raceways to finish growing to market size. The troughs and small raceways in
the hatchery building all have screened QZs at their bottom ends. The troughs,
small raceways, and their corresponding QZs all are cleaned daily. The troughs
and raceways all have a separate drain line that allows the cleaning wastewater
to be diverted to the OLS pond. Water flow has been measured for the trough
and small raceway QZ drains and is 30 gpm and 75 gpm, respectively. Quiescent
zone cleaning flows are recorded and used in the calculations for the discharge
from the OLS pond. Water used in the hatchery building is diverted from the
influent ditch below the weir and is discharged to the head ditch above the first
raceways near pond #la. Mortality from the hatch house is disposed of with
mortality collected from the raceways.
Mortality: Mortalities generally range from 1% to 7% of fish on hand, now that
the raceways are screened, and depending on the disease and timing of the
disease outbreak. Normal operational mortality is disposed of in a "mort pit,"
dug for this purpose. The mort pits are dug at least 100 ft from any surface water.
None of the mort pits previously used are closer than 1A mile from the nearest
well. Soil depth in the area is generally 10 ft. Below the soil is fractured basalt.
Depth to ground water is about 45 ft. Mort pits are dug not deeper than 6 ft in
depth to allow for 4 ft of soil above the basalt. As the mort pit is used, soil and
lime are applied in layers to prevent odors and vector attraction, and aid in the
decomposition of the material. The mort pit is full when it gets with 2 ft of the
surface and then is covered with soil from the initial excavation.
Therapeutants: All drugs, disinfectants, and chemicals used at this facility are
used in a manner consistent with label directions. Therapeutants are only used as
needed. Therapeutant use at this facility has been infrequent in the past. All
drugs, disinfectants, and chemicals are stored in a cabinet in the office building
in their original containers. The chemical cabinet is in a dry well-ventilated place,
away from water, and with no floor drains. Material Safety data sheets for all
chemicals used at the facility are kept within a binder in the chemical cabinet.
Treatments are only made up for the amount necessary for immediate use. Water
from disinfection treatments is neutralized prior to discharge. Records are kept
as required by the NPDES permit for all drug and chemical usage, including the
use of medicated diets. Medicated diets are stored away from normal diets and
used as recommended.
Disposal ofBiosolids: Sludge and slurry that have been collected in the OLS
pond are recycled by land application to nearby cropped fields. Farmers that
accept the slurry must agree to disc it under within 24 hours of application and
prior to any irrigation water being applied to the field. All land application must
be done in such a manner as to prevent the materials from entering surface or
ground waters. The dates, locations, concentration, and amounts of land
B-5
-------
APPENDIX B: EXAMPLE BMP PLAN
application are kept in a record. Fields used for land application are approved by
IDEQ prior to application. FantaSea Farm works with local farmers to insure that
the land applied biosolids are applied at agronomic rates appropriate for crop
and soils conditions.
Endorsement: This BMP plan has been written and endorsed by FantaSea
management and staff responsible for the day-to-day operations and
maintenance of the facility.
B-6
-------
APPENDIX B: EXAMPLE BMP PLAN
Ideal Springs
FantaSea
Fish Farm
Figure 1: Facility Diagram
B-7
-------
APPENDIX B: EXAMPLE BMP PLAN
CERTIFICATION OF COMPLETION AND IMPLEMENTATION OF THE
BEST MANAGEMENT PRACTICES PLAN
FantaSea Fish Farm
ID-G13-0000
This BMP plan has been written, reviewed and is being implemented at FantaSea
Fish Farm. The BMP plan is available to employees and IDEQ, EPA, and IDA
upon request.
Facility Owner/Operator
Submitted (date) , which is within 9 months of receiving
authorization to discharge.
B-8
-------
APPENDIX C
BMP FACT SHEETS
-------
-------
APPENDIX C: FACT SHEETS
Fact Sheet #1:
Feed management in
flow-through and
recirculating systems
What is feed management?
Good feed management minimizes
nutrient inputs into pond water. The
primary operational factors
associated with proper feed
management include development
of precise feeding regimes based on
the weight of the cultured species
and regular observation of feeding
activities to ensure that the feed
offered is consumed. An advantage
of this practice is that proper feed
management decreases the costs
associated with the use of excess
feed that is never consumed by the
cultured species. Excess feed
distributed to systems breaks down,
and some of the resulting products
remain dissolved in the system
water.
How does it work?
Fish do not convert all of the applied
feed to flesh. The difference between
the input of a substance in feed and
the amount of a substance in the
harvested fish represents the amount
of the substance that enters the pond
ecosystem as uneaten feed and in
fish feces and metabolites. Uneaten
feed and feces are decomposed to
metabolites, like carbon dioxide,
ammonia, and phosphate, by pond
bacteria. These substances are
nutrients for the production of
phytoplankton, and they also
represent potential pollutants in
pond effluent. Nutrient inputs and
phytoplankton abundance increase
as feeding rates increase. Mechanical
aeration is used to maintain
adequate levels of dissolved oxygen
and encourage the oxidation of
ammonia to nitrate by nitrifying
bacteria. Deterioration of water
quality from increased nutrient
inputs stresses fish, and causes them
to eat less, grow slowly, and be more
susceptible to disease. Lowered
water quality in ponds also increases
the pollution potential of pond
effluents.
Practices
1. Uneaten food should be avoided.
Feed waste should not exceed
3% to 5%.
2. Do not overfeed fish.
3. Store feed properly to reserve the
nutrient quality. Minimize humidity to
prevent growth of molds or bacteria on
feed. Follow manufacturers'
recommendations for feed shelf life.
4. Handle feed with care to prevent
fines. If fines are present, remove and
dispose of them properly.
5. Know the feed requirements of the
cultured species to determine percent of
body weight per day. Use size of fish,
water temperature, projected growth
rates, and biomass in the system to
determine appropriate feeding rates
(Westers, 1995).
6. Use high quality feeds to improve
feed conversions and efficient use of
nutrients.
C-l
-------
APPENDIX C: FACT SHEETS
Implementation Notes
• Feeding by hand ensures
observation of fish feeding
behavior.
• Feed only the amount that
will be consumed in 20
minutes. (US Trout Farmers
Association, 1994)
• Generally, frequent feedings
of smaller amounts are better
than giving the day's ration in
a few feedings (IDEQ, n.d.)
• Oxygen levels drop
dramatically where large
amounts of feed are fed at one
time.
• Fish should be fed during the
coolest parts of the day in hot
weather; reduce feeding when
water temperatures reach 65-
70 F for trout. Feeding in low
oxygen environments reduces
dietary efficiency and can
result in fish health problems.
• Use of demand feeders allow
fish to set the frequency and
duration of feeding.
• Blowers may also be used to
distribute feed in raceways or
tanks, or automated delivery
systems that supply discrete
amounts of feed frequently
over a long period of time.
• Regardless of method of feed
distribution, it is important to
observe feeding behavior and
prevent overfeeding.
• Overfeeding can affect the
health of the fish by leading to
liver and kidney problems.
• Excess feed results in
economic losses and degrades
the water quality, which can
impact the health of the fish.
Additional Resources
Westers, H. 1991. Operational waste
management in aquaculture
effluents. In Nutritional
Strategies and Aquaculture
Waste. C.B. Cowey and C.Y.
Cho, eds. University of
Guelph, Ontario, Canada.
Pp. 231-238.
Cho, C.Y., J.D. Hynes, K.R. Wood,
and H.K. Yoshida, 1991.
Quantitation of fish culture
wastes by biological
(nutritional) nutrient dense
(HND) diets. In Nutritional
Strategies and Aquaculture
Waste. C.B. Cowey and C.Y.
Cho (Eds)., University of
Guelph, Ontario, Canada.
Pp. 37-50.
C-2
-------
APPENDIX C: FACT SHEETS
Fact Sheet #2:
Feed management in
pond systems
The following is based on Alabama
Aquaculture BMP no. 7, "Feed
Management," by Auburn
University and U.S Department of
Agriculture.
What is feed management?
Good feed management minimizes
nutrient inputs into pond water.
How does it work?
Fish do not convert all of the applied
feed to flesh. The difference between
the input of a substance in feed and
the amount of a substance in the
harvested fish represents the amount
of the substance that enters the pond
ecosystem as uneaten feed and in
fish feces and metabolites. Uneaten
feed and feces are decomposed to
metabolites, like carbon dioxide,
ammonia, and phosphate, by pond
bacteria. These substances are
nutrients for the production of
phytoplankton, and they also
represent potential pollutants in
pond effluent. Nutrient inputs and
phytoplankton abundance increase
as feeding rates increase. Mechanical
aeration is used to maintain
adequate levels of dissolved oxygen
and encourage the oxidation of
ammonia to nitrate by nitrifying
bacteria. Deterioration of water
quality from increased nutrient
inputs stresses fish, and causes them
to eat less, grow slowly,
Channel Catfish feeding at the surface of the
water. Source: www.aquanic.org, 2002.
and be more susceptible to disease.
Lowered water quality in ponds also
increases the pollution potential of
pond effluents.
Practices
1. Select high quality feed that contains
adequate, but not excessive, nitrogen
and phosphorus.
2. Apply feed uniformly across the
surface of the pond using a mechanical
feeder.
3. Avoid over feeding by observing fish
feeding behaviors. Do not apply more
feed than the fish will eat.
4. Maintain adequate levels of
dissolved oxygen. Fish stressed by poor
water quality conditions will be less
efficient in their ability to convert feed to
flesh.
5. For catfish ponds, daily feed
application should not exceed 30 Ib/ac
in unaerated ponds. In ponds with 2 hp
of aeration per acre, daily feed
application usually can be increased to
100 to 120 Ib/ac. These feed amounts are
maximum amounts to be applied on a
given day, not annual averages.
C-3
-------
APPENDIX C: FACT SHEETS
Implementation Notes
• Because feed management is
the main source of nutrients
in pond systems, good feed
management, reasonable
stocking rates, and adequate
aeration are effective tools for
enhancing effluent quality
• Mechanical feeders spread
feed evenly around the edges
of the pond to ensure that fish
have an opportunity to eat an
adequate amount of feed.
• One sign of overfeeding is the
accumulation of feed in the
corner of the pond.
• Overfeeding is costly and
results in unnecessary
nutrient inputs into the pond.
• Several factors influence feed
consumption including water
temperature, poor
environmental conditions like
low levels of dissolved
oxygen or high concentrations
of ammonia, and disease or
parasite problems.
• Managers need to observe the
feeing behavior of fish to
avoid overfeeding.
Additional Resources
Auburn University and U.S.
Department of Agriculture
(USDA). 2002. Alabama
Aquaculture BMP fact sheets,
No. 7: Feed Management.
-------
APPENDIX C: FACT SHEETS
Fact Sheet #3:
Erosion Control for
Pond systems
The following is based on Alabama
Aquaculture BMP No. 4, "Pond
Management to Minimize Erosion."
What is erosion control?
Erosion occurs in ponds as a result of
wave action, water currents from
aerators, inadvertent damage from
vehicles and other farm equipment,
and rain impacting bottoms, dams
and embankments of empty ponds.
Soil particles suspended by erosion
increase total suspended solids (TSS)
concentrations in pond waters and
effluents, and clay particles increase
turbidity. Sediment that has been
removed from ponds but improperly
disposed of can erode and cause
contamination of surface water with
suspended solids.
Erosion can also occur within the
pond watershed on the sides and
tops of pond embankments, in
emergency spillways, and from farm
roads around the pond, access roads
to the farm, and stream crossings.
These sources of sediment increase
suspended solids concentrations and
turbidity in pond waters.
Erosion control minimizes the input
of solids added to pond waters and
also reduces the levels of suspended
solids in pond effluents.
How does it work?
Within the pond, wave action causes
water to impact on embankments
and detach soil particles. Grass cover
above the normal water level on the
wet side of embankments provides
protection from wave action. Erosion
will be most severe when water
levels are low and bare soil is
exposed to waves and rain. Aerators
can also increase erosion by
generating strong water currents that
can suspend soil particles from the
pond bottoms and detach soil
particles from pond banks. Sediment
accumulates in ponds over time, and
eventually the sediment will need to
be removed. If sediment is placed in
unvegetated piles, rain falling on the
piles will cause erosion and the
runoff will have high concentrations
of suspended solids.
Within the pond watershed, erosion
form soil surfaces can result from
rain events that loosen soil particles.
Runoff flowing downslope can
suspend and transport the loose
particles. The energy of flowing
water can result in gullies. Bare soil
exposed on farm roads or the tops of
embankments erodes easily. Erosion
potential also increases with a
steeper slope. Livestock traffic can
also expose bare soil or create paths
that erode. If cattle wade in ponds,
they will suspend sediment and
increase turbidity.
Erosion control within watershed for
roads, dams, and embankments
involves protecting the land surface
from the impacts of rain events.
C-5
-------
APPENDIX C: FACT SHEETS
Protecting all soil surfaces with
vegetation or gravel
Practices
1. Close drains as soon as the
maintenance or other activities for which
the pond was drained are completed.
2. If possible, prevent damage to levees
or embankments caused by equipment
or vehicles. If damage does occur, make
repairs immediately to prevent erosion.
3. Stationary mechanical aerators
should be installed so that water
currents caused by these devices do not
cause erosion of pond banks or bottoms.
4. Tractor-powered emergency aerators
should be positioned to avoid erosion.
5. Sediment should be used where
possible to repair pond earthwork. If
sediment is removed from ponds, it
should be stabilized to prevent erosion.
6. Earthen berms, rip rap, or vegetation
can be used to minimize erosion from
wave action in the pond.
7. Control erosion in watersheds by
providing vegetative cover, eliminating
gully erosion, and using diversions to
route water away from areas of high
erosion potential.
8. Eliminate steep slopes on farm roads
and cover these roads with gravel,
especially roads build of soil with a high
clay content.
9. Use a 3:1 (horizontal: vertical) ratio or
flatter side slopes for pond
embankments in new construction.
10. Provide grass cover on sides of pond
dams or embankments and grass or
gravel on tops of dams or embankments.
11. NRCS recommends that new ponds
or extensions of existing ponds should
be constructed to maintain 40% to 50%
of the owner's 100-year flood plan area
near the channel.
Implementation notes
• For watershed ponds, enough
watershed area to supply
water to fill ponds during the
winter and spring is desirable;
however, excessive overflow
from ponds could cause
erosion of pond outlet
structures and increase total
suspended solids in effluents.
• Diversions can be useful for
controlling water within the
watershed. A diversion is a
channel constructed across
the slope with a supporting
ridge on the lower side.
• Maintain storage between the
top of the overflow pipe
(approximately 3 to 4 in) and
the surface of the water.
(See diagram)
C-6
-------
APPENDIX C: FACT SHEETS
Fact Sheet # 4:
Discharge manage-
ment for ponds
The following is based on Alabama
Aquaculture BMP No. 2, "Managing
Ponds to Reduce Effluent," and
Alabama Aquaculture BMP No. 10,
"Managing Ponds to Improve
Quality of Draining Effluent."
What is discharge management?
Ponds can release effluents due to
overflow from rain events and when
they are intentionally drained.
Effluent volume can be reduced by
operating ponds to maximize storage
capacity to reduce overflow and by
draining ponds only when
necessary. Discharge management
applies practices to reduce the
volume of water discharged and to
improve the quality of the effluent
discharged.
How does it work?
Water may be intentionally
discharged from ponds to facilitate
harvests or to improve the quality of
the water in the pond by flushing or
exchanging the water with new
water additions.
For catfish ponds, draining may
occur any time during the year.
Scheduling drainings, when
possible, to minimize the release of
sediment and nutrients can reduce
the potential pollutants in pond
effluent.
Practices
1. When possible, construct seine-
through ponds that do not have to be
drained for harvest.
2. Harvest fish by seining and without
partially or completely draining the
pond unless it is necessary to harvest in
deep ponds, to restock, or to repair pond
earthwork.
3. Avoid flushing new supplies of
water into the pond by discharging a
portion of the production water.
Research has proven mechanical
aeration to be a more effective method of
preventing low dissolved oxygen levels
than the practice of water exchange.
4. Maintain the water level below the
tops of the overflow pipes. When make-
up water is added it should be kept 3 to
4 in below the tops of overflow pipes,
preventing storm overflow.
5. Design new ponds with structures
that allow ponds to be drained near the
surface instead of from the bottom.
Where practical, alter drain structures for
surface discharge when old ponds are
drained for harvest or renovation.
6. Typically ponds must be drained
completely after about 15 to 20 years to
repair earthwork. When ponds must be
drained completely, it is recommended
that the final 20% to 25% of the pond
volume be discharged into a settling or
held for 2 to 3 days to minimize
suspended solids and then discharged
slowly.
7. If possible, install a swivel-type drain
that can take in water from the surface
and lowered to completely drain the
pond. (Most catfish pond drains usually
C-7
-------
APPENDIX C: FACT SHEETS
have the discharge pipe inlet at the pond
bottom.)
8. Use riprap at discharge points.
Implementation Notes
• During final draining the
valve should be opened to
one-quarter its maximum
capacity. At the beginning of
rainfall the valve should be
closed and not reopened until
the water has cleared.
• Where ponds are located in
close proximity of one another
water from the pond being
drained for harvest can be
transferred to adjacent ponds
for reuse.
Additional Resources
Auburn University and U.S.
Department of Agriculture
(USDA). 2002. Alabama
Aquaculture BMP fact sheets,
No. 2: Managing Ponds to
Reduce Effluent Volume.
------- |