AQUIFER CHARACTERISTICS AND MIXING RATIOS AT NAINITAL LBF SITE

Abstract

The water supply system at Nainital is quite different in India, where the water supply is due to bank filtration mechanisms. In Nainital there are 12 tube wells out of which 8 tube wells are in good operating conditions nearby lake area at a distance of less than 100 m. The studies are carried out is mainly to analyze the sub surface inflow to lake and outflow to the ground from the lake obtained through the isotope method. The water from the tube wells is the groundwater under the influence of surface water from Nainital lake and seepage water flowing through faults and fractures from Sukhataal sub-catchment therefore the water drawn from the tube wells is expected to be different from the lake water depending upon the mixing ratio of the bank filtrate and groundwater . The concentration of major ions is likely to be more in the tube wells water than the lake water. The hydraulic conductivity was also determine at selected tube wells by pumping test, sieve analysis and falling head test along with hydraulic gradient to estimate travel time from the lake to the tube wells.