Use of fresh water for watering of garden and lawns of big premises like university, landscape irrigation of multinational companies, municipal corporations and townships at the outskirts of cities, gardens and golf course of military formations is becoming impracticable due to water crisis and is more true in summer. About 80 % of water supplied to consumers gets converted in to sewage. Sewage is rich in plant nutrients and when it reaches to water bodies like river, lake it encourages the growth of algae, water hyacinth and degrades the water quality. Recycle and re-use of wastewater is need of the time for water conservation. Nutrients from the sewage can be recycled back to soil by the use of treated sewage for gardening and agriculture where huge volume of water is required every day. Cluster of population have septic tanks for sewage treatment and disposal. Providing an engineering solution to environmental problems at optimum resources is a challenging task. The present paper makes an effort towards the sustainable development of sewage treatment by suggesting a methodology to upgrade an existing septic tank.