Upgrading a Small Wastewater Treatment Plant for the 21st Century

Fremont, Nebraska, USA is a city of approximately 25,000 people located in the central U.S. The city is served by a wastewater treatment plant (WWTP) that was originally constructed as a primary treatment plant in the 1960s and subsequently expanded to secondary treatment in the 1970s. Typically, wastewater treatment plants in the United States are designed for a life of 20 - 25 years for process equipment while structures are expected to serve longer. In the early 1990s, the City of Fremont began planning for the future of wastewater treatment for their community. This planning effort was necessitated for the following reasons:Regulatory agency discharge permit modificationsTreatment technology changesAging of existing systemsCapacity issues for both liquid and solids streamThis paper will discuss the steps taken and results achieved by the City of Fremont to upgrade their wastewater treatment plant for the twenty-first century.