New Delhi, Oct. 30 -- The Delhi Jal Board (DJB) has floated an expression of interest (EoI) for treatment technology that can make the city's most contaminated groundwater fit to drink, as it looks to meet a summer supply deficit of around 250 million gallons per day. The EoI, issued on October 16, invites technology providers and research institutions to install systems that can remove high concentrations of dissolved salts, heavy metals and other contaminants from groundwater. The target is groundwater along the Najafgarh drain, at Garhi Mandu and in other areas where levels of total dissolved solids, heavy metals and other contaminants are significantly high. "The proposed technology should be capable of treating groundwater with TDS lev...