WATER QUALITY IMPROVEMENT DURING RIVERBANK FILTRATION AT HARIDWAR

Abstract

Surface water, the primary source of drinking water requires a extensive treatment prior to supply. Ground water is fit for drinking purpose without any treatment or with minimum treatment. Water level of ground water is decreasing. As level of ground water decreases, the pumping cost are increases. The quality and quantity of ground water are also affected after the continuous pumping. River Bank Filtration (RBF) is a natural treatment method for potable water applications. It is the source for continuous recharging of production wells. The cost is considerably reduced. There were 16 production wells at the bank of the River Ganga in Haridwar till 2009. Water quality of these wells was evaluated in 2005-06. As a preparatory step for the Kumbh 2010, six more production wells were commissioned. A necessity was felt to assess the water quality of 16 production wells after a gap of 5 years and 6 new wells commissioned in 2009-10. In this project, efforts have been made to identify water quality of source water (river/canal), production wells water and tube wells water. Twenty-three samples were collected monthly from January to April 2011 for the analysis of physical, chemical and bacteriological water quality parameters. Water quality parameters such as electrical conductivity, major ions and total organic carbon were recorded more in water samples from the production wells located north of New Supply Channel (NSC) than the south of NSC. A batch experiment with two different soil samples and water from canal in Roorkee was carried out for 48 hr to assess the leaching property of aquifer material in water. An attempt has been made to simulate steady state groundwater flow model to predict the flow path of groundwater/bank filtrate and measure travel time for three production wells in the north by using Processing MODFLOW version 5.3.0. Influence of two production wells on each other was observed through the steady state groundwater modelling.