Cost-Effective Implementation of an Integrated Fixed-film Activated Sludge Process: Accommodating Economic Development for the City of Twin Falls

The City of Twin Falls is in need of a significant expansion of their wastewater treatment plant (WWTP), allowing for the continued economic growth in the service area. The existing WWTP capacity is rated at 36.3 mega liters per day (MLD) on an average day maximum month (ADMM) basis, with influent flow and loads exceeding this value. Planning progressed with the City to find a method of financing for the treatment facility expansion, providing a cost-effective WWTP capacity expansion, and ensure that the overall WWTP site buildout capacity is maximized to meet future service area needs. Through a detailed evaluation and selection process, the integrated fixed-film activated sludge (IFAS) treatment process was determined to be the most cost-effective approach for the City of Twin Falls. The design, contracting approach, and follow-on construction techniques promoted an expedited schedule, meeting the City’s capacity needs at their treatment facility in the required timeframe.