WATER QUALITY AND EUTROPHICATION STATUS OF THE RENUKA LAKE, DISTRICT SIRMAUR (H.P.)

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1 Journal of Indian Water Resources Society, Vol 32, No. 3-4, July-Oct., 2012 WATER QUALITY AND EUTROPHICATION STATUS OF THE RENUKA LAKE, DISTRICT SIRMAUR (H.P.) Omkar Singh and M.K. Sharma ABSTRACT The regular monitoring and assessment of lake water quality and its eutrophication is very important for proper conservation and management purposes. Water quality monitoring and analysis of the Renuka lake was carried out for various physico-chemical, bacteriological and trace elements during 2006 to The principal component analysis of 26 water quality parameters was performed which reveals seven principal components (eigen values greater than 1) explaining 86% of variability. These components are: (i) TDS, (ii) Hardness, (iii) Bacteriological (FC & TC), (iv) Eutrophication (Phosphate, Nitrate), (v) Dissolved Oxygen, (vi) Cadmium, and (vii) BOD, respectively. The lake water quality was assessed as per BIS standards for drinking purpose, which has shown the mean concentration of total coliform, faecal coliform, iron, manganese, lead and cadmium beyond the permissible limits for drinking purpose. The eutrophication of the Renuka lake follows a decreasing trend from hypertrophic to eutrophic indicating necessity of regular measures for conservation and restoration. Key Words: Physico-Chemical, Bacteriological, Trace Elements, Eutrophication, Principal Component Analysis INTRODUCTION Renuka lake is an important religious lake of Himachal Pradesh. A state level fair is organised at Renuka lake annually in which thousands of devotees visit the lake for holy bath and worship in the temples situated at the site. Many devotees also offer flour pallets/balls to the fish roaming in the lake even after restriction. The various activities such as bathing/washing, fish feeding, grazing, de-forestation, agroforestry etc. are deteriorating lake water quality as well as enhancing eutrophication of the lake. The Renuka lake has been subjected to suffer from various problems viz., deterioration of lake water quality, soil erosion & siltation of the lake causing shrinkage of the lake and eutrophication. The eutrophication is clearly visible in the lake by observing excessive growth of water hyacinth which is manually removed time to time. National Wetland Management Committee of the Ministry of Environment & Forests (Govt. of India) has recognized the Renuka lake as one of important wetlands of the Himalchal Pradesh needs conservation and management on priority basis (State Council for Science, Technology & Environment, Govt. of HP). Reddy & Char, (2004) also recommended need for conservation and restoration measures for this lake. During year 2005, the Renuka lake was included in the list of Ramsar Sites in India attaining international importance under the declaration of Ramsar Convention on wetlands. STUDY AREA Renuka lake lies at Latitude N and Longitude E at an elevation of 645 m above mean sea level. The lake is oblong in shape flanked by two parallel steep hills running nearly east west. The lake rests in a long valley and the surrounding slopes are covered with a variety of vegetation and thick woods. The supply of the lake is through nallahs 1. National Institute of Hydrology, Roorkee , Uttarakhand (India), E.Mail (Corresponding Author): omkar@nih.ernet.in Manuscript No draining the catchment and numerous underlying springs. The land uses in the catchment include: 0.5% urban, 9.5% agriculture and 90% sub-tropical deciduous reserved forest composed of broad leaves, sal, bamboo etc. A wildlife sanctuary is also in the lake catchment. The geology of the Renuka lake shows the sedimentary rocks comprising carbonaceous shale, slate, siltstone, purpled dolomitic limestone and intrabedded red shales of tertiary period (Singh et al., 1987). A brief information about the Renuka lake is given in Table 1. Table 1: A brief information of the Renuka lake (H.P.) S. No. Details of Renuka Lake 1 District Sirmaur 2 Type of lake Rural 3 Latitude ' 36 N 4 Longitude ' 30 E 5 Altitude (m) Maximum depth (m) 13 7 Minimum depth (m) Mean depth (m) *Maximum length (m) *Width (m) Shoreline length (m) Surface area (m 2 ) Catchment area (ha) 254 (* Source: SCSTE, Govt. of H.P., Shimla) REVIEW Various limnological studies are reported in the lakes of Western Himalayan region covering J&K, Himachal Pradesh and Uttarakhand (Zutshi, 1989; Omkar & Sharma, ; Jain et al., 1999, Kumar et al. 1999, Kumar et al. 2006; Das and Dhiman, 2003; Shewa, 1998, Rai et al; 2006, 2007, Singh et al., 2010). Anshumali and Ramanathan (2007) have studied seasonal variation in the major ion chemistry of Pandoh Lake located in the Lesser Himalaya of the H.P using Principal Component Analysis. However, limited studies are available 1

2 J. Indian Water Resour. Soc., Vol. 32, No. 3-4, July-Oct., 2012 of the Renuka lake. Singh et al.(1987) have studied the Renuka lake in respect of its morphometry and catchment characteristics. Major ion chemistry of the Renuka lake and weathering processes have also been reported (Das & Kaur, 2001; Anonymous, 1996, 2004). Reddy & Char (2004) have reported status of various lakes in India and advocated immediate attention for restoration of a number of lakes including the Renuka lake of Himachal Pradesh. METHODOLOGY The water quality investigations were carried out during 2006 to 2008 in the Renuka lake. The water samples were analysed for various physico-chemical ( ph, EC, TDS, DO, BOD, COD, Ca, Mg, Na, K, alkalinity as CaCO 3, bicarbonate as HCO 3, Cl, SO 4, NO 3, PO 4, F, Hardness ), bacteriological (faecal coliform, total coliform) and trace elements (Fe, Mn, Cu, Ni, Pb, Cd, Zn). The sampling and analysis was made following standard methods (APHA, 1985). Standard Water Sampler (Make: Hydro Bios, Germany) was used to collect water samples in the lake. Water quality of the lake was assessed for drinking purpose (IS-10500: 1991, re-affirmed in 2003). The eutrophication status of lake was carried out using Trophic State Index (Carlson, 1977). Principal Components Analysis (PCA) was carried out for 26 water quality parameters using Systat Software. RESULTS AND DISCUSSION The statistical analysis of water quality data pertaining to years 2006 to 2008 was carried. The results are given in Table 2. Table 2: Statistical data of water quality parameters for the Renuka lake Parameters N Minimum Maximum Mean Std. Variance Mean Std. Error Deviation ph TDS DO BOD Hardness Alkalinity as CaCO Bicarbonate SO PO NO F Na K Ca Mg Fe Mn Cu Ni Pb Cd Zn Cod TC FC Cl The ph variation from 5.8 to 9.0 (mean: 7.13) indicates slightly acidic to alkaline nature of lake water at different locations. The acidic reaction could be due to decomposition of carbonaceous material which is entering the lake from deciduous forest around the lake/catchment. However, the mean value of ph is indicative of alkaline nature of the lake water. The mean COD to BOD ratio (12.4/1.8 = 6.9) of the lake water was found below 10.0, which indicates the abundance of biodegradable substances in the water. The dissolved oxygen (DO) was found to vary from mg/l (mean 6.7) from bottom to surface. The bottom of the lake was found under anoxia. The concentration of various water quality parameters in the lake viz., phosphate varies from mg/l (mean: 0.16 mg/l), nitrate varies from mg/l (mean: 4.3 mg/l), sulphate varies from mg/l (mean: 113 mg/l), TDS varies from mg/l (mean: 364 mg/l), BOD varies from mg/l (mean: 1.8 mg/l), hardness varies from mg/l (mean: 287 mg/l), total 2

3 Fig. 1: Frequency plot of Faecal Coliform (MPN/100 ml) observed during in the Lake Fig. 2: Frequency plot of Dissolved Oxygen (mg/l) observed during in the Lake 3

4 coliform varies from MPN/100 ml (mean: 61 MPN/100 ml), faecal coliform varies from MPN/100 ml (mean: 50 MPN/100 ml), respectively. The sample diagram showing frequency analysis for faecal coliform and dissolved oxygen are given in Figs. 1 & 2. Principal Component Analysis of Lake Water Quality Data The principal component analysis of water quality was performed for 26 water quality parameters (ph, TDS, DO, BOD, COD, alkalinity as CaCO 3, hardness, bicarbonate, sulphate, chloride, phosphate, nitrate, fluoride, sodium, potassium, calcium, magnesium, iron, manganese, copper, nickel, lead, cadmium, zinc, total coliform, faecal coliform) monitored during 2006, 2007 and 2008 (Table 3 & 4). Accordingly, seven components (eigen values greater than 1.0; Davis, 1986) were found useful to study water quality pattern explaining the variability of total data upto 86%. The first component, accounting for 24.7% of the total variance, heavily weighted on TDS, sulphate, lead and ph. High loading of TDS factor could be associated with weathering processes of rocks and subsequent dissolution of ions in water. Second J. Indian Water Resour. Soc., Vol. 32, No. 3-4, July-Oct., 2012 component heavy weighted on hardness, calcium, alkalinity, bicarbonate and magnesium explains 24% of the total variance. Third component explains 8.97% of the total variance was heavily weighted Faecal colliform and total colliforms and designated as bacteriological component indicating bacterial contamination of lake. Fourth component explains 7.78% of the total variance was found to heavily loaded phosphate and nitrate and which was designated as eutrophication component. These nutrients are controlling factor in eutrophication of the lake attributed through a complex processes of lake-catchment interactions through anthropogenic activities. Fifth component was heavily attributed to Dissolved Oxygen and Copper, which accounts for 9.55% of the total variance. The lake remains under anoxia specially during winter, therefore, the DO component plays a very important role and appropriate measures could be necessary for improvement of the DO and health of the Renuka lake. Sixth component was heavily attributed to Cadmium and COD, which accounted for 5.88% of the total variance. Seventh component was heavily attributed to BOD, which accounted for 5.14% of the total variance. Table 3: Eigen values and variance explained by the PCA Components Eigen values variance explained % of total variance explained Cumulative % of variance Drinking Water Quality Status The water quality of the Renuka lake was compared on the basis of desirable and permissible limits as prescribed by the Bureau of Indian Standards (IS-10500: 1991, re-affirmed in 2003) using data for 2006 to The results are given in Table 5, indicating mean concentration of magnesium (41 mg/l), total coliform (61 MPN/100 ml), faecal coliform (50 MPN/100 ml), iron (1.49 mg/l) and manganese (0.87 mg/l) beyond the desirable limits. Also, the mean concentration of lead (mean: 0.35 mg/l) and WQ Variables cadmium (mean: 0.01 mg/l) were exceeding the desirable limits in this study having no further relaxation beyond their desirable limits, respectively. The mean concentrations of total coliform (mean: 61 MPN/100 ml), faecal coliform (mean: 50 MPN/100), iron (mean: 1.49 mg/l) and manganese (mean: 0.87 mg/l) were found beyond the permissible limits for drinking purpose. Therefore, the Renuka lake water requires appropriate water treatment measures prior to be used for drinking purpose. Table 4: Important principal components deciphered from water quality data for Renuka lake Principal Components TDS SO Pb ph Na Cl K Fe Mn Ni Hardness

5 Ca Alkalinity HCO Mg FC TC PO NO DO Cu Zn F Cd COD BOD Table 5: Water quality assessment of the Renuka lake for drinking purposes Substance or Characteristic (Desirable Limit) Permissible Limit Water Quality Status of the Renuka lake ph 6.5 to 8.5 No Relaxation (7.13) Total Hardness (mg/l), Max (287) Iron (mg/l), Max (1.49) Chlorides (mg/l), Max (1.8) Dissolved solids (mg/l), Max (364) Calcium (mg/l), Max (49) Magnesium (mg/l), Max (41) Copper (mg/l), Max Manganese (mg/l), Max (0.87) Sulfate (mg/l), Max (113) Nitrate (mg/l), Max. 45 No relaxation (4.3) Fluoride (mg/l), Max (0.71) Cadmium (mg/l), Max No relaxation (0.01) Lead (mg/l), Max No relaxation (0.35) Zinc (mg/l), Max (0.15) Alkalinity (mg/l), Max (165) Faecal coliform (MPN/100 ml), Max. Nil Nil (50) Total coliform (MPN/100 ml), Max. Nil (61) Dissolved Oxygen (mg/l), Min (6.7) Eutrophication Status In the present paper, eutrophication status of the Renuka lakes was also attempted on the basis of limited base data of phosphate (Singh, et.al., 1987; Anonymous, 2006) in addition to the data observed under the present investigations. Accordingly, Trophic State Index (Carlson, 1977) was computed and a trend of eutrophication was obtained for surface and bottom of the lake. Fig. 3 shows that the Renuka lake was under hypereutrophic condition for the past several years. The eutrophication trend was found to be decreasing which indicates effect of ongoing conservation and restoration measures by the Government. However, further data on water quality and restoration measures would guide more distinctly about eutrophication of the lake. 5

6 J. Indian Water Resour. Soc., Vol. 32, No. 3-4, July-Oct., 2012 Fig. 3: Eutrophication status and trend for the Renuka lake CONCLUSION In this study, water quality monitoring was carried out for various physico-chemical (ph, EC, TDS, DO, BOD, COD, Ca, Mg, Na, K, Alkalinity as CaCO 3, HCO 3, Cl, SO 4, NO 3, PO 4, F, Hardness ), bacteriological (faecal coliform, total coliform) and trace elements (Fe, Mn, Cu, Ni, Pb, Cd, Zn) during 2006, 2007 and The principal component analysis of lake water quality was performed for 26 parameters showing importance of seven principal components (eigen values greater than 1.0), which are useful to explain lake water quality pattern under this study. These components are: (i) TDS, (ii) Hardness, (iii) Bacteriological (FC & TC), (iv) Eutrophication (Phosphate, Nitrate), (v) Dissolved Oxygen, (vi) Cadmium, and (vii) BOD, respectively. Apart from above, the lake water quality was assessed for drinking purpose as per BIS standards. The results have shown total coliform (mean: 61 MPN/100 ml), faecal coliform (mean: 50 MPN/100), iron (mean: 1.49 mg/l) and manganese (mean: 0.87 mg/l) beyond permissible limits for drinking purpose. The mean values of lead (mean: 0.35 mg/l) and cadmium (mean: 0.01 mg/l) were also found to exceed the desirable limits or otherwise permissible limit in cases of these two elements having no relaxation. Dissolved oxygen (DO) of the Renuka lake was found to vary from mg/l (mean: 6.7 mg/l) from bottom to surface of lake indicating hypolimnion under anoxia. Eutrophication status of the Renuka lake was observed relatively higher. However, the trend was found to decrease from hypertrophic to eutrophic level during the study. Appropriate conservation and restoration measures would be necessary to adopt for further reducing the existing eutrophication level of the Renuka lake. REFERENCES 1. APHA, Standard Methods for the Examination of Water and Waste Water. American Public Health Association, Washington D.C. 2. Anshumali and Ramanathan, A.L., Seasonal Variation in the Major Ion Chemistry of Pandoh Lake, Mandi District, H.P., India. Applied Geochemistry, Vol. 22, 8, pp Anonymous, Report on Water Quality Monitoring of Renuka Lake. H.P. State Pollution Control Board, Shimla. 4. Anonymous, Report on Water Quality Monitoring of Renuka Wetland. H.P. State Environment Protection & Pollution Control Board, Shimla. 5. Carlson, R.E A trophic state index for lakes. Limnology and Oceanography. 22: Das, B.K. and Kaur, P., Major Ion Chemistry of Renuka Lake and Weathering Processes, Sirmaur District, H.P., India. Environmental Geology, Vol. 40, pp Davis, J.C. (1986). Statistics and data analysis in geology. 2 nd Ed. John Wiley & Sons, New York. 8. IS-10500:1991. Drinking Water Specifications, Bureau of Indian Standards, New Delhi. 9. Kumar, B., Jain S.K., Nachiappan, Rm. P., Rai, S.P., Kumar Vinod, Dungrakoto, V.C. and Rawat, Y.S., Hydrological studies of lake Nainital, 6

7 Kumaun Himalayas, Uttar Pradesh. Final Project Report, National Institute of Hydrology, Roorkee. 10. Kumar, V, Rai, S.P. and Singh, Omkar, Water Quantity and Quality of Mansar lake in the Himalayan Foothills, India. Intl J. of Lake & Reservoir Management, Vol. 22 (3), pp Omkar and Sharma, Water Quality Studies of Surinsar Lake in Jammu Region. Report - CS (AR) 157, NIH, Roorkee, pp Rai, S.P., Kumar, V., Singh, O., Kumar, B. & Jain, S.K., Bathymetry, Sedimentation Rate and Physico-Chemical Characteristics of Mansar Lake in the Himalayan Foothills, J&K, India. J. GSI, Vol. 67, pp Rai, S.P., Kumar, V., Singh, O., Jain, S.K., Hydrochemical Characteristics of Mansar Lake, J&K in India. J. IE (I)-EN, Vol. 88, pp Reddy, M.S. & Char, N.V.V., Management of Lakes in India. ( of_lakes_in_india-10 Mar04.pdf) 15. Shewa, W. A., Eutrophication analysis of lakes of Kumaun region. M.E. Dissertation, Dept. of Civil Engg., IIT, Roorkee, pp Singh, O., Sharma, M.K., Choubey, V.K. and Singh, R.D., Water Quality 17. Evaluation of the Renuka Lake (H.P.), IPU J. of Env. Sciences, Vol. iv, No. 3, pp Singh R., Mishra, S.H., Shyamananda, R.K., Sharma, G., Mahajan, I. & Aggarwal, B.K., Morphometry and catchment study of Renuka lake, Himachal Pradesh, India, with a note on its flora and fauna, In: Western Himalayas. Vol. II (Eds Pangtey, Y.P.S. and Joshi, S.C.), Gyanodaya Prakashan, Nainital, pp Zutshi, D.P., Years of ecological research on the lakes of North-Western Himalaya. In: Singh J.S. and Gopal I.B. (eds.) Perspective in Ecology, Jagmaudar Book Agency, New Delhi, pp