The City of Glendive operated discharging wastewater treatment lagoons. The City received a new MPDES discharge permit containing new limits and further analysis indicated a high likelihood of future permit limits for ammonia, TN, TP, e.Coli, and metals. The City’s existing lagoons could not meet these limits, so they worked with Great West Engineering to evaluate alternatives for treatment system improvements, which lead to their decision to construct a new wastewater treatment plant. The City installed the first Intermittent Cycle Extended Aeration System (ICEAS) in Montana. The ICEAS is a continuous flow biological treatment system with a simplified process. The system brings process, aeration, decanting, and control together in a single treatment tank and is fully automated to redue the complexity of operation. The project also included changing the point of discharge from Glendive Creek to the Yellowstone River without being considered a “new and increased source”.