Optimization in the Design of Sewer Network

Abstract

Sanitation is the basic prerequisite of public health and is vital to break the transmission of the disease cycle. Both onsite and offsite sanitation are systems in practice. Most of the urban sanitation system is tending towards underground sewerage pattern. As per the present scenario, only 35% of the urban population have been provided with an underground sewerage system in India. The developing countries like India do not have 100% of sewerage system due to capital-intensive infrastructures and unaffordable budget. There is an inherent need for cost optimization of such a system to enhance affordability with reduced cost. newlineThe Cost of the sewerage system includes Collection, Conveyance, and Treatment and recycling. Of the three, the collection system shares about 65% of the project cost, hence optimization of sewer collection system becomes inevitable. Such a scenario will help to increase the coverage of the sewerage system within the allocated budget. newlineThe literature review indicates that most of the research has minimized the project cost considering the optimized matrix of the pipe cost, laying and jointing including manhole cost. Various application techniques such as Dynamic Programming, Linear Programming, Non-Linear Programming, Heuristic Methods, Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), Genetic Algorithm have been considered for optimization. The bedding cost, choices of material, limitation in the depth of cutting, sewer network as a whole with lift station have been seldom considered. However, the design constraints such as depth of flow and velocity as specified in the manuals and guidelines have not strictly adhered in the earlier research study. Also, commercially available sizes have not been considered in the optimization. The application software commercially available has only the ability to carry out hydraulic design and analysis. However, the optimality has to be decided manually by the user.