Towards Sustainable Cities: Life Cycle Cost Analysis of the Construction of a Novel Wastewater Management System

Wastage of water is one of the most common environmental issues in the modern era. However, if this level of usage can be controlled, or recirculated properly, the wastage can be lowered down to a very minimum. In the conventional residential plumbing system, blackwater and greywater gets mixed and goes through the same sewage pipe. This mixture turns the whole wastewater amount into blackwater, which requires complex treatment before discharge. Greywater on the other hand can be discharged to waterbodies requiring almost zero treatment. In this study, a new wastewater management method is proposed where the plumbing system is split into separate lines for blackwater and graywater. Since greywater represents the largest share of wastewater in a residence, this separation makes this large amount of greywater distinctly available for discharge or reuse. On the other hand, the lesser amount of blackwater reduces the resource requirement for treatment, opening the possibility for smaller wastewater treatment plants. This smaller wastewater treatment plants will result into a significant reduction in costs for the city, as well less environmental impact. However, the separation of sewage pipes will also require some extra construction costs alongside, such as double piping, and excavation. This anomaly necessitates a life cycle cost analysis to determine the ultimate feasibility of this system. Therefore, this study also conducts a life cycle cost analysis to justify this system on a hypothetical residential scenario. The assessment is based on the currently established sustainable cities, for a specific set of data, such as population, water consumption, utility rates and so forth