Heavy metal pollution status of lake Nainital, Uttarakhand

The present research was carried out for a period of one year between December 2006 and November 2007 in Lake Nainital, which recognised as a national lake of India The lake provides many ecosystem services. The main objective of the present study was to determine the heavy metals (iron, copper, manganese, zinc, fluoride and arsenic) pollution of the lake, as the lake water is used for drinking water supply. Out of the 48 samples of water collected from different depths, iron and copper were detected 46% and 56%. Samples ranging from a mean concentration of 0.010 to 0.012 and 0.016 to 0.038 mg/1, respectively. Zinc, manganese and fluoride were detected in all samples ranging in concentration from 0.152 to 0.286,0.007 to 0 008 and 0.96 to 1.047 mg/l respectively. Arsenic was not detectedin any of the samples analysed. The concentration of all metals varied temporaly as well as spatially. The overall mean concentrations of iron, copper, zinc, manganese, and fluoride for the whole lake were: 0.011 ± 0.001, 0.024 ± 0.017, 0.216 ± 0.061, 0.007±0.001 and 1.00 ± 0.05 mg/1. The results of the study suggested that concentrations of all the analysed metals were within the prescribed limit of WHO and Indian Standard Drinking Water Specification. Thus the water was safe for drinking purposes after treatment.