The City of Foley, Alabama, is a coastal community with Southern charm, popular for its access to water activities, top-rated golf courses, and quaint downtown. Due to the region’s reliance on healthy bodies of water, the utility’s primary mission is to serve as stewards for the area’s aquatic environment.
Riviera Utilities Wastewater Treatment Plant at Wolf Creek had been operating a 35-year-old extended aeration oxidation ditch process to meet the needs of its 20,000 residents. Rated for only 2.0 MGD, an expansion to 3.5 MGD was necessary. Instead of adding an oxidation ditch to increase capacity, Riviera wanted to prepare for more stringent effluent requirements as well. The AquaNereda® Aerobic Granular Sludge Technology was selected to achieve these goals.
AquaNereda® was highly appealing as an innovative approach to secondary treatment for a number of reasons:
• The innate BNR capabilities provided by the layered microbial community of the granules enables the system to meet future total nitrogen and total phosphorus limits.
• The excellent setting properties of AGS allow for
MLSS of 8 g/L or higher, significantly reducing foot-
• AquaNereda® provides the lowest lifecycle cost compared to other processes.
Startup and Granulation
The system was seeded with CAS from the site’s existing oxidation ditches. Granulation was rapid with granule diameters greater than 600 μm measured just one month after startup and greater than 2,000 μm (10x larger than the minimum diameter to be considered AGS) observed after six months. By September 2020, the system had achieved the target Sludge Volume Index 5/30 ratio of 1.2, indicating excellent settling properties (see image).
Footprint and Energy
The AquaNereda® technology allows for significant footprint and energy reduction when compared to conventional processes:
• With its high operating MLSS and enhanced settling, the owner will be able to expand treatment capacity to an average flow of 10 MGD within the existing site compared to only 3.5 MGD with the oxidation ditch process.
• Reduced equipment needs and more efficient aeration contribute to a specific energy consumption rate of less than 0.3 kW-hr/m3 resulting in an overall power cost reduction of approximately 40%.
Aqua-Aerobic Systems is dedicated to ensuring customer satisfaction. Our commitment to producing quality equipment and process designs along with superior customer service has led to a happy customer in Foley, Ala.
“The AquaNereda® process was selected in order to future-proof our investment for wastewater treatment for the next 25 years,” Lee Kibler, superintendent of water and wastewater operations at Riviera Utilities, said. “Granular sludge is the wave of the future. Aqua-Aerobic is an outstanding supplier and highly invested in the future development of this technology in North America.”
The Riviera Utilities WWTP Upgrade received distinction for Wastewater Project of the Year at the 2021 Global Water Awards. WW
Aqua-Aerobic Systems Inc. provides advanced solutions in aeration and mixing, biological processes, cloth media filtration, membranes, disinfection and process control. Learn more at www.aqua-aerobic.com.