Water Quality Assessment of the Central Himalayan Lake, Nainital
Madhuben Sharma
University of Petroleum and Energy Studies, Bidholi, Dehradun, Uttarakhand 248007, India
Correspondence should be addressed to Madhuben Sharma; madhubensharma06@gmail.com
Received 14 July 2014; Revised 28 October 2014; Accepted 20 November 2014; Published 10 December 2014
Academic Editor: Paul M. Bradley
Copyright © 2014 Madhuben Sharma. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
e Nainital Lake, situated in the central Himalayas of India, is an important water body and a major tourist spot. is study aims to identify factors or processes that determine the water quality of the lake. For this purpose, water samples from two di erent points were collected—highly polluted (Mallital) and least polluted (Tallital)—to represent the actual level of pollution in the lake in four di erent seasons (January, April, July, and October). e collected samples were analyzed for di erent physical and chemical parameters. In order to assess the state of the lake’s water quality, the samples were compared with the standard water quality values. Turbidity, electrical conductivity, total alkalinity, and heavy metal (lead, iron, and copper) concentration were found to be above the desirable limit of the prescribed national and international standards in all four seasons at both Mallital and Tallital. Reasons a ecting the water quality were found to be natural (thermal strati cation and lead-bearing rocks) and anthropogenic (domestic sewage, runo , and illegal construction activities in the vicinity of lake). Various lake restoration alternatives/interventions have been suggested that can lead to an improvement in the lake’s water quality, such as a orestation, phytoremediation, and sediment basin.
1. Introduction
Nainital city is one of the major tourist attractions in the northern part of India. e lake provides water to 40,000 local inhabitants [1] and thousands of tourists visiting it every year [2] who use the water for di erent purposes like drinking and for recreational activities [3, 4]. Increasing local population, logarithmic increase in the tourist ux in Nainital, and the concomitant mushrooming of a large number of hotels in the catchment area have severely a ected the water resources and biodiversity of this watershed [5, 6].
According to Singh et al. [7], open sewers disposing large quantities of sewage in the lake are de nitely caus- ing a detrimental e ect on the lake water quality. Other anthropogenic activities such as illegal construction, litter, domestic discharge, and recreational use of lake water are major concerns for sedimentation and eutrophication of the lake water [1].
us, considering it as imperative, this comprehensive primary water quality monitoring study of the Nainital Lake has been undertaken. e main objective of this paper is
to assess the state of water quality of the Nainital Lake by carrying out a comprehensive monitoring exercise to identify the contributing factors for the existing water quality. For this purpose, water samples were collected from a highly polluted and a least polluted site of the lake; 18 physicochemical parameters were analyzed to understand the limnology of the Nainital Lake. Various possible measures that can be put in place to maintain the desired water quality have also been discussed.
2. Materials and Methods
2.1. Study Area. e Nainital Lake is a natural kidney-shaped, tectonic, warm monomictic-type lake, situated at 29∘ 24 N latitude and 79∘ 28E longitude [5]. It covers a surface area of 48 hectares. e maximum and mean depths of the lake are 27.3 m and 16.2 m, respectively [2]. It is divided into two subbasins (Mallital and Tallital) by a 100 m wide transverse underwater ridge, 7m below surface [5]. Mallital (north basin) is a highly polluted site due to intense boating activity and Naina Devi Mandir drain emptying into it. Tallital (south
2 Advances in Environmental Chemistry Table 1: Drinking water quality standards, units, analytical method, and recommending agencies (source: [8–10]).
Water quality
pH
Turbidity
Dissolved oxygen Electrical conductivity Total dissolved solid Total suspended solid
Temperature
Biochemical oxygen demand
Total hardness Total alkalinity Chloride Sodium Potassium Phosphate Lead
Copper Iron Zinc
Unit
pH unit
NTU
mg/L
