A Mixed Integer Programming Analysis of Effluent Treatment Options Proposed for Pond Production of Hybrid Striped Bass, Morone chrysops X M. saxatilis

Abstract

The growth of aquaculture farming has resulted in increased scrutiny by regulatory agencies. The Environmental Protection Agency (EPA) added aquaculture into the Effluent Limitation Guidelines (ELG) program that bases its rulemaking effort on technology-based standards that are economically achievable. The primary objective of this paper is to evaluate several effluent treatments that have been considered for hybrid striped bass (HSB), Morone chrysops X M. saxatilis, farming in pond production systems. A mixed integer programming (MIP) analytical model for HSB farming was developed focusing on maximizing profit derived from HSB production subject to the imposition of several different effluent treatment options. Settling basins and constructed wetlands entail high costs for farmers with high reduction in effluents. Filtering treatments incur high cost without much reduction in nutrient concentration in effluents. Not flushing water from the pond, or not draining the pond annually, reduces effluent volume. Reduction in the amount of water flushed or drained from the pond also decreases operating costs without any additional investment cost associated with adoption of the treatments. It is estimated that various effluent treatment options would increase production costs on average by $0.001-6.79 per kg. The main result of the MIP model is that no annual draining and not flushing the pond water are the best operational treatments. When effluent level standard regulations are imposed on effluent discharge, the model selected the no draining treatment. By not draining ponds, farms would minimize treatment cost by reducing effluent volume. Additional work is needed on the long-term risks associated with not flushing or not draining HSB production ponds.