Assessment of Old Sewerage Networks by Using Asset Management and Failure Mode Analyses Case study South Campus of Sudan University of Science and Technology

Abstract

For wastewater management utilities, asset management can be defined as managing Infrastructure capital assets to minimize the total cost of owning and operating them, while delivering the service levels customer’s desire. The study Campus consists of four colleges, teaching staff houses in addition to girls` hostel. Data for this study were collected from available records; personnel interviews and field surveys. The Level of service of network was defined, performance goals were selected and all data were entered into sewer Cad Program for analysis and solving bottleneck problems and to build and prepare Information system. Network was evaluated based on international materials cost and national labor cost.. The Failure modes& risk management were assessed and the conditions of the sewer network assets were determined. The South Campus network had a main sewer line with 769 meter total length (Asbestos cement and PVC) and its depth starts from 2 meters to 11meters, it has 19 main manholes and one pump station. This Network serves 20,804 persons in the campus with total calculated capacity (Q= 650 mᶟ d). The analysis with Sewer Cad program showed the present performance of the studied network by detailed profiles and the main network problems found to be the over discharge and low pumping rate. Two modeled solutions were suggested to solved these problems .First (Pump Design Solution) and the other solution (wet well design Solution). 3 The total value of the network found to be 31,348.25 $$, Condition assessment reflects Fair to Good condition of this network with grades of 2-3. Risk Priority Numbers (RPN) were calculated and found to be in the range of 2 to 72 with the greatest RPN of failure modes as 72 for pump power failure and the lowest RPN was 2 for manholes corrosion. This network is very valuable; of good to fair condition; and can be well maintained with periodic preventive maintenance plans and erection of call centers with acceptable time of response to failures after applying one of the above suggested solutions to overcome the existing problems. 4