Do you Need Tertiary Filters at your Wastewater Tratment Plant? Which Technology Should You Pick and Why?

In Florida the requirements for both high-level disinfection and advanced wastewater treatment (AWT) dictate the need for tertiary wastewater filtration. Traditionally plants have used traveling hood automatic backwash (ABW), upflow continuously backwashed, or deep-bed granular media filters. Newer filter designs such as membrane filters, series upflow filters, high-rate disk filters, and synthetic media filters are available that offer the potential of lower costs, enhanced water quality or smaller footprints.Current water management district, FDEP, and EPA regulatory initiatives relative to reuse, numeric nutrient limits and stormwater treatment, if implemented in their current forms, will encourage utilities in Florida to look closely at these newer filtration technologies to facilitate the production of high quality reclaimed water for public access reuse, aquifer recharge, aquifer storage and recovery, or other types of high-value reuse. The City of Daytona Beach's Westside Regional Wastewater Treatment Plant (WRWWTP) has a permitted capacity of 15 mgd average day flow and uses traveling hood granular media filters to filter secondary effluent followed by ultraviolet (UV) light for high-level disinfection. Reclaimed water is pumped to their reuse distribution system or to the Halifax River during periods of low demand for reclaimed water. The WRWWTP facility has experienced operational issues with their current filters and decided to perform an evaluation of options (including newer innovative technologies) for renovating or replacing their existing filters. This paper provides the results of an economic evaluation of the capital and operations lifecycle costs for several alternatives for renovating or replacing the existing filters.