Enhanced biological phosphorus removal (EBPR) technologies convert soluble phosphorus to a solid form through microorganisms which uptake soluble phosphorus. While not fully understood, EBPR has been successfully practiced for over 10 years and is considered a proven technology for removal of phosphorus from municipal WWTPs. However, many treatment plants require nitrification and/or nitrogen removal (denitrification) as well as phosphorus removal. The combined nitrification/denitrification EBPR systems are grouped as biological nutrient removal (BNR) processes since both nitrogen and phosphorus removal must be balanced for optimum treatment plant design, operation, and performance.