Based on the LCI, life cycle assessment was performed using SimaPro. About 18 impact categories were analysed using ReCiPe 2016 Midpoint indicator to study the LCA. Among the impact categories, global warming potential (GWP), freshwater eutrophication, marine eutrophication, and stratospheric ozone depletion are the major environmentally impacting categories in all the scenarios. Conventional STP in Scenario I yielded a net GWP of 411 g CO2 Eq./m 3 (Figure ), which was mainly attributed to the energy consumption in aeration tanks, sludge thickening etc. (401 kWh/m 3 WW). Meanwhile, the GWP of STP was also influenced by factors such as type of wastewater, technology used, and materials usage . Conventional STPs using activated sludge process reported a similar GWP ranged between 240 -700 g CO2 Eq./m 3 (Campos et al., 2016; Chen et al., 2018) (Figure ). The increase in GWP was attributed towards modifying conventional processes by extended aeration and denitrification etc. When two treatment systems were combined, GHG emissions increase up to 4 times than the conventional systems .