Effluent and production impacts of flow-through aquaculture operations in West Virginia

In light of recent changes to federal regulatory requirements placed on the aquaculture industry, aquaculture operators must act proactively to maximize their production to meet demands, compete with new operations, and maintain compliance with effluent standards. As a result, water quality characterization was conducted at six anonymous facilities using flow-through design, rearing mostly rainbow trout (Oncorhynchus mykiss) that were selected based on various water sources, operation, size, and effluent treatment. Average concentrations and mass loadings of regulated parameters were within regulatory limits and increased in direct proportion to the mass of fish reared. However, when comparing effluent pollutant concentrations and loads with West Virginia National Pollutant Discharge Elimination System (NPDES) permit limitations, the potential for increased production existed at each facility. Based on the current West Virginia NPDES limit of 30mg/L for total suspended solids (TSS), each facility could increase production from 147 to 819%. However, with a more stringent TSS limitation of 5mg/L net used in states in the western US, two facilities would have to reduce production from 37 to 44%, while the other sites could increase production from 19 to 170%. Consequently, the opportunity to increase production under any set of regulatory constraints was a function of annual fish production, legal requirements, and the implementation of effective effluent treatment processes.