National Pollutant Discharge Elimination System (NPDES)

NPDES Aquaculture Permitting

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What is Aquaculture?

Aquaculture is the culture, or husbandry, of marine or freshwater plants or animals. "Aquatic animals" means all life stages of fish, mollusks, and crustaceans. Aquaculture is undertaken in a variety of ways, including:

  • fish hatcheries,
  • raceways, ponds, or recirculating systems,
  • floating or submersible net pens or cages, and
  • bag, rack, or suspended shellfish culture.

Which Aquaculture Discharges Require an NPDES Permit?

NPDES permits are required for discharges associated with:

Aquaculture Projects (40 CFR Part 122.25) -- A "defined managed water area which uses discharges of pollutants into that designated area for the maintenance or production of harvestable freshwater estuarine or marine plants or animals."

Concentrated Aquatic Animal Production Facilities (CAAP) (40 CFR Part 122.24) -- A "hatchery, fish farm, or other facility” which is designated by EPA (40 CFR 122.25) or which satisfies the following criteria in Appendix C (40 CFR Part 122).

  • Facilities raising cold water fish species or other cold water aquatic animals in ponds, raceways, or other similar structures which discharge at least 30 days per year, but does not include:
    1. Facilities which produce less than 9.090 harvest weight kilograms (20,000 pounds) of aquatic animals per year; and
    2. Facilities which feed less than 2,272 kilograms (5,000 pounds) of food during the calendar month of maximum feeding.
  • Warm water fish species or other warm water aquatic animals in ponds, raceways, or other similar structures which discharge at least 30 days per year, but does not include:
    1. Closed ponds which discharge only during periods of excess runoff; or
    2. Facilities which produce less than 45,454 harvest weight kilograms (100,000 pounds) of aquatic animals per year.

Effluent guidelines have been developed for CAAP facilities producing 100,000 pounds or more of aquatic animals per year.


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