A wastewater treatment process at a potato processing plant located in Argentina was experiencing continuous upsets with their activated sludge treatment system. After an initial assessment, it was determined that the upsets were caused by inadequate training. A hands-on training program was implemented to teach operators how monitor and control the two existing biological treatment processes (Anaerobic and Activated Sludge). The operators were trained on the following: collecting representative samples and operations data; calculation of quantitative data and control variables (food to microorganism [F/M], sludge volume index [SVI], solid retention times [SRT], etc.) and; assessment of qualitative data. The training was supported with an operations and maintenance manual prepared specifically for that wastewater treatment process.