Cost Comparison Analysis of Wastewater Treatment Plants: A Case Study of Kabul City

Ahmad Wahid Sekandari

Faculty of Water Resources and Environmental Engineering, Kabul Polytechnic University, Kabul, Afghanistan

Abstract: Cost estimation is a significant consideration for the development and evaluation of sewage treatment plants. This chapter evaluated the most cost-effective treatment scheme among the different sewage treatment plants that were designed in chapter four for the study area. Project and annual operation and maintenance (O&M) costs of integrated anaerobic-aerobic sewage treatment plant (IA-ATP) were compared to waste stabilization pond (WSP) and complete-mix activates return sludge sewage treatment plant (ARSTP). For an average sewage flow of 9379 m³/day with BOD and SS of 350 mg/L and 360 mg/L, respectively, costs of sewage treatment in integrated anaerobic-aerobic treatment plant, waste stabilization ponds, and complete-mix activates return sludge sewage treatment plant were evaluated in 2015 US dollars. Results indicated that project costs of the ARSTP and WSP were higher than IA-ATP by about 14% and 34%, respectively. Consequences also showed that the annual O & M of the ARSTP cost was tremendously higher than the IA-ATP and WSP by about 109%. Per unit cost of sewage treatment in the IA-ATP, was estimated at USD 1.10/m³, while the values for the ARSTP and WSP were USD 1.36/m³ and USD 1.46/m³, respectively. Apparently, the IA-ATP was obviously the most-cost effective sewage treatment scheme for the study area.