Nero Engineering

The City of Osakis currently operates and maintains a water treatment plant (WTP) consisting of conventional gravity iron/manganese filters followed by an ion exchange softening system. Since its startup in 2012, the WTP has struggled to operate properly and efficiently, due primarily to the presence of ammonia in the groundwater source. In collaboration with City staff, Nero conducted a biological iron and ammonia removal pilot study and successfully demonstrated the effectiveness and efficiency of the process in treating the high levels of ammonia. Upon successful completion of the pilot study, Nero evaluated different designs to incorporate the process into a full-scale system and determined that the most cost-effective solution consists of a new pressure filter for biological iron removal followed by rehabilitation of the existing gravity filter for biological ammonia removal. Nero then helped the City secure the necessary funding for the WTP improvements, as well as funding for rehabilitation of the City’s aging water tower, through USDA Rural Development and brought the project to bid in Spring of 2023. The improvements project is now moving forward with construction scheduled to start in 2024 and final completion in Summer of 2025.