Pakistan is a country with a population of 185 million people. Almost 26 percent of the total vegetable is being irrigated through untreated wastewater. Wastewater irrigation poses many health hazards to humans and other grazing animals. Rising population and depleting per capita water availability accentuate the need to treat wastewater before its re-use to meet the need of growing food requirement. Study aims at finding the best suitable method of treating urban wastewater keeping in view the dynamics of Pakistan and site specificity of the Twin-Cities of Rawalpindi and Islamabad. Two widely adopted wastewater treatment techniques namely Sequence Batch Reactor (SBR) and Constructed Wetland (CWT) have been compared and a cost and benefit analysis is done on the basis of construction and operating costs, operative efficiencies and effectiveness. Moreover, impacts of wastewater on the yield of three major crops of Pakistan including wheat, rice and sugarcane have been simulated. Primary data is used for all comparisons and related analysis. On the basis of the findings it can be confidently said that CWT is more cost effective, both in terms of construction and operating costs, when compared with SBR thus making it more suitable for an energy deficient country like Pakistan. Per gallon cost of treated wastewater is much lower in case of CWT. SBR, on the other hand, has a slight edge over CWT in terms of effectiveness. Treated wastewater has a positive effect on crop yield. Supervisor:- Dr. Rehana Siddiqui