Rejuvenation of water bodies with recycled water

Abstract

This study investigated the new routes of groundwater replenishment in water-constrained urban communities. Against the present water demand of 1,440 million gallons per day (MGD) in Delhi, 1,000 MGD including 140 MGD groundwater is being supplied. Additionally, residents, institutions and commercial occupants are illegally extracting 250 MGD. This groundwater extraction is enormous in comparison with the water injected into the ground through rain water harvesting, resulting in the tremendous depletion of the groundwater table. The aim of the study is to replenish groundwater with tertiary treated effluent available round the year. The study is conducted on one natural water body rejuvenated in the South and another artificial water body constructed in West Delhi with the objective of determining whether groundwater can be replenished with tertiary treated water with an improved quality, and whether it can be replicated elsewhere. The qualities of the groundwater and water tables were checked before and after rejuvenating the water bodies. The utilization of tertiary treated effluents has resulted in raising the groundwater tables from 5 to 7 m and improved the quality of the groundwater in the past 2 years. This practice can be replicated elsewhere as done in Brisbane (Australia) and Singapore.