Treatment of Urban Run Off Using Constructed Wetlands in New Delhi, India

The River Yamuna forms an integral part of the Indo-Gangetic plains. Delhi, capital of India, constitutes only 2% of the entire catchment area of the River Yamuna. The pollution problem posed by urban wastewater discharges from open storm drains owes its origins to the inadequate development of sewerage systems in the city, coupled with sharp increases in population stemming from the industrial revolution. Early approaches to mitigate pollution load in river under Yamuna Action Plan (YAP) were focused on the treatment of domestic as well as industrial wastewater, whereas the issue of urban runoff remained completely untouched. The present research is directed at the development of constructed wetlands, in order to achieve an optimal solution to the requirement to treat sewage (treated as well as untreated) and urban runoff whilst meeting environmental requirements of the receiving water. The availability of land was a problem on the banks where the drain meets the river; hence a methodology is proposed to transfer the drain water by means of aqueducts to the opposite bank, where there is availability of unused floodplains of the river. For the entire treatment setup it is found that even though initial investment required is huge but the running and maintenance cost is very low as compared to conventional sewage treatment plants. It is concluded that if implemented correctly these wetlands would not only provide an ideal solution to help curb the problem of pollution but also create a healthy natural ecosystem near the riverbanks.