Indian Journal of Science and Technology

Abstract

Artificial recharge of groundwater using treated wastewater continues to rise, especially in arid and semi-arid countries. Artificial recharge as a means to enhance the natural supply of groundwater aquifers is becoming increasingly important in groundwater management. The present pilot study aims to planning and designing of artificial recharge structures for an ideal housing complex using treated waste water generated within the complex. Basic operational water requirement is estimated to quantify the water to be recharged for a balanced and sustainable water recharge cycle. The study estimated the volume of generated waste water as well as rainfall runoff water from the ideal housing complex. The rate of natural ground water recharge, rainfall runoff and total treated effluent available for recharge is estimated as additional or alternative source of recharge. Detailed Hydro geological study has been carried out to explore subsurface profile by drilling the bore holes in different locations inside the study area. A confined aquifer was found at a level of 4m to 8m in decreasing levels. The soil stratum below the aquifer was found impervious. Hence boring of recharge shafts up to a depth of 4m to reach a confined aquifer layer will be the best suitable method for recharging the aquifer. The depth of aquifer is varying from 3m to 6m. Water fluctuation during monsoon and non-monsoon period was found to be around 5m. The estimated water demand is 1.6 MLD. Based on the Rational Formula, the runoff quantity is estimated as minimum of 13.48 MLD and maximum of 55.47 MLD. Thus the study identifies the significant quantity of runoff from the study area during the monsoon periods. The total estimated effluent available for recharge is estimated as 1.28 MLD. By considering the sources available, hydro geological conditions, the recharge pond and recharge shaft is designed. It encourages not only the maximum utilization of available natural resources but it helps in reducing the demand for freshwater and sustaining the vulnerable resources for future.

Keywords: Artificial Recharge, Chennai Metropolitan Area, Groundwater, Treated Waste Water, Hydrogeology, Recharge Shaft