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Managing Aquaculture to Protect Water Quality
How NPDES Permits for Aquaculture Facilities Protect Water Quality
On this page: * Pollutants of Concern for Aquaculture * NPDES Permits for Aquaculture * Aquaculture Water Quality Management
Aquaculture Topics * Overview * NPDES Permitting * Managing Aquaculture to Protect Water Quality * Federal Collaborations
Pollutants of Concern for Aquaculture
Pollutants of concern often associated with aquaculture include: * Total suspended solids, settleable solids * Biological wastes (metabolic waste, unconsumed feed) * Floating and submerged matter * Five-day biochemical oxygen demand, low dissolved oxygen * Nutrients (phosphorus and nitrogen), ammonia * Drugs that are unconsumed or unmetabolized * Chemicals, such as anti-fouling agents
NPDES Permits for Aquaculture
NPDES permits establish regulatory frameworks to set pollution controls and demonstrate that those controls are working. This 10-minute video describes how NPDES permits applies to discharges from aquaculture operations.
Aquaculture Water Quality Management
NPDES permits for aquaculture facilities include effluent limitations that control the discharge of pollutants. Effluent limitations may be numeric or narrative. Numeric limits specify the maximum amount of a pollutant that may be discharges over a certain period, usually a day or a month. Narrative limits include Best Management Practices (BMPs) or requirements to minimize or eliminate discharges. NPDES permits for concentrated aquatic animal production (CAAP) facilities that produce 100,000 pounds or more of aquatic animals must include requirements to implement the effluent guidelines established at 40 CFR Part 451Exit EPA’s website. These facilities are subject to reporting requirements regarding: * The use of certain drugs; * Unanticipated discharges; and * Developing and maintaining a BMP plan.
CAAP facilities using flow-through and recirculating systems and net pens are subject to additional requirements dictated by the effluent guidelines. NPDES permits for these facilities include requirements for: * Solids control (flow-through and recirculating systems only); * Feed management, waste collection and disposal, transport or harvest discharge, and carcass removal (net pens only); * Materials storage; * Maintenance; * Recordkeeping; and * Training.
NPDES permits for non-CAAP aquaculture facilities may contain similar requirements. Sometimes, NPDES permits for both CAAP and non-CAAP aquaculture facilities may require other water quality management activities, such as monitoring for drug and chemical application, or escape prevention and response plans. Explore the interactive graphics below to learn more about common types of BMPs that may be included in NPDES permits for flow-through and net pen aquaculture facilities. Select each activity for a description of how it protects water quality. The activities shown are examples only and may not be required or appropriate at every aquaculture facility. Refer to the applicable NPDES permit to determine which activities are required for a specific facility.
Best Management Practices for Flow-Through Aquaculture
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General Reporting Requirements
Reporting the use of certain drugs and the occurrence of unanticipated discharges makes permitting authorities aware of such discharges.
General Reporting Requirements
Best Management Plans (BMPs) ensure that producers have procedures in place to control discharges of pollutants from the facility. Annual updates ensure the plans account for facility changes and new or innovative BMPs.
Solids Control
Efficient feed management helps control discharges of solids and nutrients.
Solids Control
Routine cleaning of rearing units and settling basins minimizes discharge of accumulated solids.
Solids Control
Removal and disposal of animal mortalities and wastes keeps them out of the receiving water.
Material Storage
Proper storage of feed, drugs, chemicals, and pesticides reduces chances of leaks and spills.
Material Storage
Prompt cleanup of leaks and spills prevents pollutants from entering the receiving water.
Structural Maintenance
Routine inspections by facility staff help identify damage and necessary repairs.
Structural Maintenance
Regular maintenance keeps facilities functioning properly to maintain efficiency and prevent unintended discharges.
Recordkeeping
Maintaining records on feeding, number and weight of aquatic animals, cleaning, inspections, maintenance, and repairs provides documentation that the operator has implemented required management activities.
Training
Training staff on proper spill prevention, operation, and cleaning procedures prepares them to prevent and respond to accidental discharges and spills, operate the system efficiently, and reduce discharges of solids and nutrients.
Other Water Quality Management Activities
Source water monitoring provides information on levels of pollutants in the intake water. Some permits require source water monitoring, particularly where intake credits or net limits are allowed.
Other Water Quality Management Activities
Effluent monitoring helps assess pollutant levels and verify compliance with NPDES permit conditions.
Other Water Quality Management Activities
Proper application of drugs and chemicals prevents them from entering the receiving water.
Other Water Quality Management Activities
Properly siting production system and discharge points prevents adverse environmental impacts (e.g., to endangered or threatened species and their critical habitat and historical sites) and other use conflicts (e.g., water use, navigation, or other local or state requirements). View a text version of the graphic, Best Management Practices for Flow-Through Aquaculture.
Best Management Practices for Net Pen Aquaculture
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General Reporting Requirements
Reporting the use of certain drugs and the occurrence of unanticipated discharges makes permitting authorities aware of such discharges.
General Reporting Requirements
Best Management Plans (BMPs) ensure that producers have procedures in place to control discharges of pollutants from the facility. Annual updates ensure the plans account for facility changes and new or innovative BMPs.
Feed Management
Efficient feed management, including real-time feed monitoring, helps control discharges of solids and nutrients.
Waste Collection and Disposal
Collection and proper disposal of feed bags, packaging, rope, and netting prevents their release to the surrounding environment.
Transport or Harvest Discharge
Proper disposal of transport water and harvest wastes (e.g., blood, viscera, carcasses) minimizes waste materials discharged overboard.
Carcass Removal
Regular and frequent removal of animal mortalities prevents their discharge to the surrounding water.
Material Storage
Proper storage of drugs, pesticides, feed, and petroleum products reduces the chance of leaks and spills.
Material Storage
Prompt cleanup of spills prevents pollutants from entering the receiving water.
Maintenance
Routine inspections help identify damage and necessary repairs to prevent release of non-native species.
Maintenance
Regular maintenance keeps facilities functioning properly to maintain efficiency and prevent unintended discharges.
Recordkeeping
Maintaining records on feeding, number and weight of aquatic animals, net pen changes, inspections, and repairs provides documentation that the operator has implemented required management activities.
Training
Training staff on proper spill prevention, operation, and cleaning procedures prepares them to prevent and respond to accidental discharges and spills, operate the system efficiently, and reduce discharges of solids and nutrients.
Other Water Quality Management Activities
Proper net hygiene practices prevent discharges of biofouling organisms, solids, and anti-fouling chemicals.
Other Water Quality Management Activities
Properly siting net pens prevents adverse environmental impacts (e.g., to endangered or threatened species and their critical habitat and to historical sites) and other use conflicts (e.g., water use, navigation, or other local or state requirements).
Other Water Quality Management Activities
Escape prevention and response plans ensure that producers have procedures in place to prevent fish escape and can take action in the event fish escape occurs. View a text version of the graphic, Best Management Practices for Net Pen Aquaculture.
National Pollutant Discharge Elimination System (NPDES)
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