HYDERABAD: Being a resident of Hyderabad, you may know that groundwater is polluted, but are you aware about the extent of contamination? Researchers who studied
water balance equation for Hyderabad found that nine out of 10 litres of water that trickles into groundwater table is not contributed by precipitation (rainfall). It means for every litre of rainwater that seeps in , nine litres of municipal and industrial waste water percolates into groundwater table.
Water leaking from underground water pipelines of Hyderabad Metropolitan Water Supply and Sewerage Board (HMWSSB) also contributes to groundwater table. While this source of water is minimal, major contribution to groundwater table comes from open nalas and polluted lakes, besides the contaminated river Musi. The researchers found that net urban recharge component of groundwater was 568mm per year, but only 53mm per year was through natural (rainwater) recharge.
Urban recharge component of groundwater is higher (10 times) than natural recharge. Urstated recent study in latest issue of the science journal,
International Soil and Water Conservation Research.
The study was carried out by Hemant Balwant Wakode, Klaus Baiera, Ramakar Jha and Rafig Azzam. They are drawn from Department of Engineering Geology and Hydrogeology, RWTH Aachen University, Germany and Civil Engineering Department, National ban recharge component includes water supply network and
sewage network. There is a higher possibility of groundwater recharge from non-transported sewage, as large area of Hyderabad is still not covered by sewage network. Most of the surface reservoirs are polluted due to direct discharge of sewage into lakes, Institute of Technology, Patna. They utilised remote sensing and GIS techniques to estimate natural recharge from precipitation, actual evapotranspiration and surface run-off.“In projects aiming at increasing use of groundwater, adequate analysis of potential of existing aquifers must be conducted and no withdrawal above the mean annual total recharge rate should be allowed,” they said.
Representative image 
