Feasibility of Retention Structures, Settling Basins, and Best Management Practices in Effluent Regulation for Alabama Channel Catfish Farming

The United States Environmental Protection Agency has initiated rule making for aquaculture effluents. The contents of the rule will not be finalized until June 2004, but effluent containment in retention structures, effluent treatment in settling basins, and best management practices have been components of rules for other animal production facilities. The main aquaculture activity in Alabama is pond culture of channel catfish (Ictalurus punctatus). Fish are harvested with seines, and it is not necessary to drain ponds more than once in 5 to 10 years. Thus, effluents result mainly from storm overflow in winter and early spring. Catfish ponds in Alabama cannot be operated without effluent. A retention structure of enormous size would be necessary to retain storm overflow without discharge. Treatment of storm overflow by sedimentation also is not feasible. Settling basins with enough volume to provide a hydraulic retention time of 8 h would often be larger than production areas. Most catfish farms in Alabama are built to property lines or streams, and there would seldom be enough space available for settling basins to treat draining effluent. The best approach to effluent management in Alabama catfish farming appears to be the development and implementation of best management practices (BMPS) to reduce the volume and improve the quality of effluents. Considerable research has been conducted on water quality in catfish production ponds, and there is a large database to use in forming BMPs. Several categories of BMPs are provided for consideration as follows: BMPs to reduce effluent volume; BMPs to minimize suspended solids through erosion control; BMPs to improve pond water and effluent quality; BMPs for use of therapeutic agents and other chemicals; BMPs for siting and construction of new ponds or farms. Suggestions on how a formal system of BMPs could be prepared for Alabama catfish farming are given.