This case study explores how Medellín, Colombia’s 2018 state-of-the-art Bello Wastewater Treatment Plant has revitalized both the river and its surrounding community. The Medellín River flows through Colombia’s second-largest city, between Aburrá and Medellín. Since the early 20th century, it has experienced significant environmental challenges with sanitation, stemming from sewage, industrial discharge, and riverside settlements. By analyzing the history of wastewater treatment in Colombia and throughout South America, this case study provides insights into the complexities of managing urban water bodies and the importance of collaborative, sustainable approaches to ensure the health and vitality of industrial water systems.