BONITA SPRINGS EAST WATER RECLAMATION FACILITY SLUDGE-DRYING SYSTEM SELECTION PROCESS

In 2003, Bonita Springs Utilities (Bonita Springs, FL) began preliminary design of its new 4 mgd East Water Reclamation Facility (EWRF). During initial planning, the utility decided to pursue the option of thermal drying for treating the residuals from both its existing West Water Treatment Facility (WWRF) and the new EWRF. The WWRF lime stabilizes its waste-activated sludge and contract-hauls the Class B material for final disposal, but this option has become less and less desirable. The number of available contract haulers and application sites in the area has declined to the point where the utility is receiving only one bid for its annual biosolids contract. In addition, the State of Florida has begun evaluating current land-application rules and is drafting language that could lead to greater restrictions on Class B land application. These two issues were the main drivers for pursuing a technology that would produce a more marketable and sustainable treatment and disposal option for the utility.With all the drying technologies available, it was critical to create an organized process that would allow BSU to investigate, evaluate and select the most appropriate drying technology and the best value for its treatment plant. The most difficult part of the process would be the development of a formal request for proposal (RFP) and evaluation process that would allow BSU to fairly compare completely different drying systems.