Pakistan has now essentially exhausted its available water-resources and is on the verge of becoming a water-deficit country. The per-capita water availability has dropped from 5,600 m to 1,000 m. The public water-requirement has risen manifolds, as population is increasing, industry is growing and we are bringing more area under cultivation to meet the increasing demand for agriculture-products. The quality of groundwater and surface-water is low and is further deteriorating because of unchecked disposal of untreated municipal and industrial wastewater and excessive use of fertilizers and insecticides. This paper presents an overview of various low-cost treatment options for the treatment of municipal wastewater-treatment.