BENEFICIAL REUSE OF GREASE TRAP WASTE AND SEPTAGE THROUGH SURFACE LAND APPLICATION (AS AN ALTERNATIVE DISPOSAL METHOD FOR MUNICIPAL WASTEWATER FACILITIES)

Spartanburg Sanitary Sewer District (SSSD) is undergoing an 80 million upgrade of their largest wastewater treatment facility. In the initial design meetings, the operations staff requested to have all grease trap waste, which is presently treated in the wastewater treatment facility, removed from the treatment process. Several alternatives for managing the grease were discussed including the option of treating all grease trap waste and septage in a separate location and land applying the blended product. This paper will discuss this proposed project and anticipated results.Product Development: Treating grease trap waste with septage will require a “special blend” of grease trap waste, septage and waste activated solids. Lime stabilization will be used to treat the blended product prior to land application. SSSD is working with Clemson University to develop the proper ratio of grease trap waste : septage : waste activated solids for an end product that can be surface applied and beneficial to a variety of crops for “year round” application. SSSD and Clemson University are also exploring the development of the best type of application equipment to use and the best type of blending equipment to derive a beneficial end product.Program Management: SSSD will work closely with septage and grease trap waste haulers to design a “user friendly” offloading station that manages the quality of raw material received at the receiving station. This station will serve as the “product blending” unit that will mix the blended waste streams with lime and remain separated from the wastewater treatment process. This allows ease of access to the facility for the septage and grease trap haulers and minimizes the operation and maintenance challenges of having grease and septage discharged in batches to the treatment process. The lime treated product will be transported to a dedicated land application site where additional treatment with lime is possible prior to land application.The land application site will be owned and managed by SSSD and will serve as a demonstration site for land application of biosolids and septage. This site will also play an integral role in SSSD's biosolids outreach program.