Wastewater - For the purposes of this general permit, wastewater is water that is a result of the following activities: Propagation, rearing, or transportation of aquatic species. Washdown, cleaning, and flushing of fabricated raceways, ponds, or other containment structures, or process equipment. Washing, treating, or any other direct contact with aquatic species. 25-Year, 24-Hour rainfall event - The maximum rainfall event with a probable recurrence interval of once in 25 years, with a duration of 24 hours, as defined by the National Weather Service in Technical Paper Number 40, "Rainfall Frequency Atlas of the United States," May 1961, and subsequent amendments, or equivalent information or state rainfall information. Part II. Permit Applicability and Coverage Section A. Discharges Covered This general permit authorizes discharges into or adjacent to in the state by certain concentrated aquatic animal production facilities, aquatic animal production facilities, and other activities related to the propagation or rearing of aquatic species through the use of ponds, lakes, fabricated tanks and raceways, or other similar structures. Categories of Authorized Discharges Level I Facility Operations that meet the following descriptions and criteria: retail bait dealers; discharges resulting from the production of crawfish in conjunction with rice farming; ponds used as pay lakes; facilities that exclusively utilize closed ponds; public or commercial aquariums; aquarium suppliers; live fish hauling tanks; any aquaculture facility that utilizes or other enclosures placed within public waters for the propagation or rearing of aquatic species with a harvest weight equal to or less than 10,000 pounds per year; or facilities that temporarily hold and do not feed aquatic species. Level II Facility Aquatic animal production facilities that meet one of the following criteria (a., b., or c.) and that do not produce shrimp in the coastal zone: Produces cold water aquatic species in ponds, raceways, or other similar structures that: discharge into surface water in the state less than 30 days per year; or
Part III. Permit Requirements Section A. Effluent Limitations This section applies to II facilities that discharge into water in the state, and all Level III and Level IV facilities. Numeric effluent limitations applicable to all Level II facilities that discharge into water in the state, and all Level III and Level IV facilities: Parameter Daily Average Limitation Daily Maximum Limitations Sample Type Monitoring Frequency1 Flow (Million Gallons per Day) Report Report Estimate or 1/day Total Suspended Solids N/A 90 mg/L Grab Inorganic Suspended Solids N/A Report (mg/L) Grab 1/month Total Residual Chlorine N/A 0.1 mg/L Grab 1/day2 pH (Standard Units) 6.0 minimum 9.0 maximum Grab 1/week 1 Monitoring frequency for Level II authorizations shall be once every six months with the exception of flow monitoring which shall be conducted daily. 2 Monitoring for total residual chlorine is required only when the effluent being discharged is chlorinated. Numeric effluent limitations applicable to all Level II, Level III, and Level IV facilities discharging to perennial streams with a head water flow greater than 2.5 cubic feet per second (cfs) and to all other water bodies: Parameter Daily Average Limitations Daily Maximum Limitations Sample Type Monitoring Frequency1 Dissolved Oxygen 5.0 mg/L minimum N/A Composite2 1/week Carbonaceous Biochemical Oxygen Demand (5-day) N/A 250 lbs/day and Report mg/L Grab 1/month Ammonia Nitrogen N/A 2.0 mg/L Grab 1/month 1 Monitoring frequency for Level II authorizations shall be once every six months.