| 503.101 | Fish and Aquatic Animal Production Facilities |
| 503.102 | Irrigation Activities |
| 503.103 | Silvicultural Activities |
| 503.APPENDIX A | References to Previous Rules (Repealed) |
| a) | A National Pollutant Discharge Elimination System (NPDES) permits is required for the construction, modification, or operation of a facility that contains, grows, or holds aquatic animals in ponds, raceways, or similar structures for production, such as a hatchery or fish farm, and that discharges for any 30 or more days per year, except that an NPDES permit is not required for: |
| 1) | A closed pond that discharges only during periods of excess runoff; or |
| 2) | A facility that produces less than 20,000 pounds of aquatic animals per year. |
| b) | An NPDES permit is required for any facility that contains, grows, or holds any species of fish or other aquatic animal life non-native to the United States and that discharges to a navigable water at any time. Non-native species of fish are identified in Special Publication No. 6 of the American Fisheries Society, entitled "A List of Common and Scientific Names of Fishes from the United States and Canada" (Washington, D.C., American Fisheries Society, 1970); except that carp (Cyprinus carpio), goldfish (Carassius auratus), and brown trout (Salmo trutta) are considered native species for this regulation. |
| a) | There is a point source of discharge (e.g., a pipe, ditch or other defined or discrete conveyance, whether natural or artificial); and |
| b) | The return flow is from land areas of more than 3000 contiguous acres, or 3000 noncontiguous acres which use the same drainage system. |