The City & County of Broomfield wastewater treatment plant secondary treatment processes were upgraded to a new biological nutrient removal process described as Integrated Fixed Film Activated Sludge (IFAS) back in 2003 using a moving bed plastic carrier element to help grow the biomass. This allows the existing aerobic reactors to maintain nitrification during year round operation while still operating near conventional activated sludge solids retention times (SRT) one would find in just carbonaceous treatment plants. The upgraded IFAS system includes anaerobic and anoxic reactors to help meet new effluent Total Nitrogen and Total Phosphorus limits.
RUTT, K. SEDA, J. JOHNSON, C.H. (2006): Two Year Case Study of Integrated Fixed Film Activated Sludge (IFAS) at Broomfield, CO WWTP. Alexandria: WEFTEC URL [Accessed: 16.04.2012]