SOLIDS MANAGEMENT CASE STUDIES FOR FIVE COMMUNITIES

Available solids management options for utilities are selected by widely varying methods. These methods not only take into account the purely technical issues, but must also include political concerns, future regulations, and local impacts. In addition, personality issues and the individual experiences of the operators and managers of the utility must be included in any evaluation. The authors have selected five small to medium-sized communities to demonstrate this and show that one solution cannot fit all situations. All of the work was conducted by CH2M HILL.The communities investigated include: Snyderville Basin Water Reclamation District, Park City, Utah; Sherman, Texas; Gresham, Oregon; Upper Trinity Regional Water District, Lewisville, Texas; and the Grand Strand Water & Sewer Authority, South Carolina.The eventual goal of each utility is to achieve Exceptional Quality (EQ) biosolids by producing biosolids that are below Table 3 pollutant levels in the Part 503 Regulations, have a pathogen density of under 1,000 MPN fecal coliforms/gram total solids, and meet one of the first eight vector attraction reduction options, also listed in the Part 503 Regulations.Although producing an EQ product sets a direction, system implementation was a key issue in all situations. Generally, most utilities do not want to spend significant capital to achieve EQ biosolids today unless public or regulatory issues are forcing them to do so. But virtually all utilities are planning for the time when they will be required to produce EQ biosolids. As such, they want to set a direction so that all future enlargements and modifications to the liquid and solids processes are made with this in mind.Interestingly, despite the fact that each project was completed by different engineers at CH2M HILL and for different clients across the country, the goals were remarkably similar. Differences in the costs of the studies, ranging from under 50,000 to over 120,000, were more a result of local public issues than the technical side.