INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 1, No 7, 2011

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1 INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 1, No 7, Muthukumar.S et al., licensee IPA- Open access - Distributed under Creative Commons Attribution License 2.0 Research article ISSN Assessment of water quality in Trichy City, Tamil Nadu, India Muthukumar.S, Lakshumanan.C, Santhiya.G, Krishnakumar. P, Viveganandann.S Center for Remote Sensing, Bharathidasan University, Thiruchirappalli muthu_nachal@rediffmail.com doi: /ijessi ABSTRACT During the last several decades, human economic activities, especially input of anthropogenic pressure have a trend of changes in the Earth and Ecosystem consuming ever increasing amounts of fresh water. Its availability at a spot is largely predetermined by the climatic and geological conditions. This study has made a systematic approach to get an idea about hydrogeochemistry of the groundwater present in the area. The region is denser with agricultural activities and industrial impact. The waters of this region is comparatively unpolluted except in few locations and weathering of minerals present in rocks were determined to be the chief factor in controlling the water chemistry of the region. An estimate on the available sources of water and need was done determine the sustainable management of water. Declining quality and quantity of water supply of the area can be attributed to the overexploitation of water and improper management of the existing resource, which needs immediate intervention. The hydrogeochemical studies of the region points out that, the present status is well within the considerable limits except for few samples. Key Words: Anthropogenic pressure, Hydro geochemistry and Overexploitation 1. Introduction Groundwater is a precious and the most widely distributed resource of the earth and unlike any other mineral resource, it gets its annual replenishment from the meteoritic precipitation. Groundwater is the largest source of fresh water on the planet excluding the polar icecaps and glaciers. The amount of groundwater within 800m from the ground surface is over 30 times the amount in all fresh water lakes and reservoirs, and about 3,000 times the amount in stream channels at any one time. At present nearly one fifth of all the water used in the world is obtained from groundwater resources. Ground water is used for agriculture, industries and domestic supply in most parts of the world as it is a replenish able resource and has inherent advantages over surface water. Agriculture is the greatest user of water accounting for 80% of all consumption. It takes, roughly speaking 1000 tons of water to grow one ton of grain and 2000 tons to grow one ton of rice. Animal husbandry and fisheries all required abundant water. Some 15% of world s cropland is irrigated. The present irrigated area in India is 60 million hectares of which about 40% is from groundwater there has been a tremendous increase in the demand for fresh water due to growth in population, advanced in practices and industrial usages. Rapid growth of urban areas has affected the groundwater quality, due to over exploitation of recourse and improper waste disposal. A person normally requires about 3 quarts (3l) of portable water per day to maintain the essential fluids of the body. Hence, there is a tendency to think of groundwater as (being) the primary water source in arid regions and of the surface water in humid regions. Hence the production and management of groundwater quality is emerging as a great public concern in India and other countries of the world. However, the quality of Received on April 2011 Published on July

2 groundwater available in an area is important as the quantity of resources. Groundwater quality studies are becoming more important in nowadays due to man made activities like domestic, industrial and agricultural activities. In urban area, the groundwater contamination occurs mainly due to domestic and industrial activities such as disposal of sewage water, septic tanks and industrial wastes. Groundwater quality studies are not critical when alternative sources are available. However, in many parts of the world, alternative supplies sufficient for the whole population particularly in urban areas, are not available. This is true in many parts of India in particular in the Tiruchirapalli District where, although the majority of the population of hut-dwellers have no option but to use shallow wells as their only source of water. The water has become a scarce commodity in the region with ephemeral rivers and vagaries in monsoon. The study area is one on such, so, it is essential to have an idea about the quality of the existing water resource, which will help in the insatiable usage is future. Hence, an attempt has been made to study the hydrogeochemistry of the groundwater of Tiruchirapalli District. 2. Aim and Objective The aim and objectives of the paper is to review the Water quality of ground water in Trichy city for domestic, Industrial and Agricultural activities. 2.1 Study Area Tiruchirappalli city is located in the part of Tamil Nadu state between 10º 38 and 11º 38 N latitude and 78º28 and 79º01 E longitude with an area of km² with population of 866,354 ( As per 2001 Survey). Figure 1: Image showing the study area map 1850

3 The city is located on the Southern bank of river Cauvery. In the top edge of the city, the river splits into two branches towards north and south direction. Kollidam is the name of the northern branch and south gets the name Cauvery. Tiruchirappalli city is located at the head of Cauvery delta and its altitude is low with 78.8 mts above the mean sea level and the city is 120 kms away from Bay of Bengal. It forms a part of a vast plain of fertile alluvia soil with a gentle but gradual slope from the west. Geologically except alluvium and soils which are at recent age, the rest of the rocks exposed in the area belong to the Archean, cretaceous and tertiary formations of these rocks types. The Archaean rock occurs north and south of cauvery alluvium. 3. Materials and Methods The water samples were collected from open and boreholes in the study area. One liter of water samples were collected polythene bottles from various wells during the month of February and March Totally thirty six samples were collected from 36 locations, for analysis various physio-chemical parameters, ph were measured by portable ph meter, EC were measured Electrode, then TDS were done by calculation method, With respect to cation, Calcium, Magnesium was analyzed volumetric method. Sodium, potassium were analyzed by flame photometry, with respect to anions chloride, Bicarbonate were done by volumetric method, Nitrate, Sulphate were estimated turbidity method. Analyzing method followed (A APHA, 1998).. Figure 2: Groundwater sample location The quality of groundwater is affected by the pumpage and natural discharge. The water is also heterogeneous in nature due to recharge from precipitation and contact with different types of rocks. Hence in the case of groundwater, the fixation of suitable sampling sites is not so easy as compared to surface water because the elements influencing water quality are not easy known. Some general suggestions can be made for the selection of sampling sites. In case, where the investigation does not take into account the changes in groundwater quality, 1851

4 the sky constituents determined in a large number of samples collected over the entire area is utilized to determine the water quality of the study area. From this, sites for selection of samples for comprehensive analysis can be fixed. If the constituents are not known at the beginning, the water quality pattern is arrived at, by first making a comprehensive analysis and thus partial analysis at other site 4. Result and Discussion The chemical concentration of different ions present in the groundwater of the study area is given in Table 5.1. The analytical precision for the measurement of major ions is about 6% to 9%. The total cations (TZ+) and total anions (TZ-) balance (Allan Freeze and Cherry 1979) shows the charge balance error (E %) percentage. The error percentage is between 2% to 10%. The correlation coefficient between TZ+ and TZ is generally occurring around 0.6 to 0.9. TDS/EC ratio ranges from 0.5 to 0.8. The role played by the other ions than those studied here for the cation and anion charge balance is lesser. Hence the composition and the range values of the ions are analyzed and discussed in detail. The groundwater in the study area is colorless and odorless in most of the places. The average temperature at the time of sampling varies from 25 C to 28 C. ph in the study area varies from 6.66 to 8.36 (Table 5.2 ). The ph average concentration in the region is EC is the ability of a substance to conduct electric current. The measure of conductivity is directly proportional to the strength of the water. The EC for purest water is 0.05 s/cm2 (Hem, 1991). In the study area EC varies from s/cm2 to s/cm2. On an average s/cm2 is observed in the region. Table 1: Chemical concentration of the sample collected in the study area (All values in mgl -1 except EC and ph) Sno ph Ec Ca Mg Na K Cl Co3 Hco3 So4 Po4 H4SiO

5 Table 2: Maximum, minimum and average concentration of different ions present in groundwater of the study area in mg/l (Except EC in μs/cm and ph) Ions Minimum Maximum Average EC ph Ca Mg Na K Cl So Hco Co TDS Scholler (1965) proposed an index to base Exchange (Chlor-alkaline indices i.e. CA11 and CA12 etc) that throw more light on the Base Exchange (Table 5.3) in the water and the rock type. All the ions are expressed in epm values. The indices show that most of the values are negative. The substances, which exchange ions, are called as permutolites (eg) clay minerals (Kaolinite, Illite, Chlorite etc., with low exchange capacity of ions, where as in Montmorillonite and vermiculite the exchange capacity of ions is higher), where CAI1 and CAI2 dominate equally. Further, in Scholler (1967) classification all the groundwaters fall in type I (Table 5.3). The table indicates that there is an exchange of Na and K in rock to that of Ca and Mg in ground water. 1853

6 Table 3: Schollers indicates and classification of groundwater in the study area S.No CAI 1 CAI 2 Well Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type-1 The ratios of different ions indicate the geochemical nature of the water (Table 5.4). The Na/(Ca+Mg) values are generally less than 1 indicating the dominance of alkaline earth over the alkalies. This may be due to the differential weathering of minerals. Table 4: The ratios of different ions indicates the geochemical nature of the water S. No. Na (Ca+Mg ) Mg'/Mg Na/Cl Na/Ca Cl/HC O 3 Cl/SO 4 Ca/Mg

7 Water quality is important criteria for determining in use for human consumption various water quality standards are available, with respect to WHO standards Table 5.5. The drinking water standards are based on two criteria 1) presence of the objectionable taste, odors, or 1855

8 colors 2) the presence of the substance with adverse physiological effects. It is controlled by health, size, age and eating habit is of the individuals. Parameter WHO Standards 1977 Highest desirable Table 5: International Standards Maximum permissible Study area Range Polluted samples Min Max (W.No.) ph TDS Calcium &30 Magnesium Chlorine ,8,9,17,23,28,30,33 Sulphate Sodium Potassium SAR values ranges from excellent to good category. According to Wilcox classification (1955) the water is classified based on the Na% with respect to the other cations present in water. Na% for water falls in permissible to unsuitable region (Table 5.6). In Na% Eaton (1950) classification of groundwater for irrigation purposes. Majority of samples fall in unsafe zone with minor representation in safe zone. Table 6: Summary of the geochemical characters of the ground water Category Grade Na% Wilcox (1955) Samples Samples Samples n=35 Category Grade n=35 Category n=35 TDS USGS Hardness Classification(USSL,1954) Excellent Soft <75 5 <200 0 Good Slightly Hard Moderately Permissible Hard Doubtful VeryHard > Unsuitable >80 8 IBE Schoeller (1965) Cation Facies Na% Eaton (1950) (Na+k)rock->Ca/Mg g.w. 21 Ca-Mg Facies 0 Safe <60 16 (Na+k)g.w.->Ca/Mg rock 14 Ca-Na Facies 35 Unsafe >60 19 Schoeller Classification (1967) Na-Ca Facies 0 S.A.R. Richards (1954) Type I 35 Na Facies 0 Excellent Type II 0 Anion facies Good Type III 0 HCO3 Facies

9 Fair Type IV 0 Poor >26 0 Corrosivity Ratio (1990) HCO3-Cl-SO4 Facies 0 Cl-SO4-HCO3 Facies 27 R.S.C. Richards(1954) Safe <1 20 Cl- Facies 8 Hardness Classification Good < Unsafe >1 15 (Handa,1964) Chloride Classification Medium (Stuyfzand,1989) Permanent Hardness (NCH) Extremely Bad >2.5 7 fresh < A EC Wilcox (1955) Very fresh A Excellent <250 0 Fresh A Good FreshBrackish Temprorary Hardness (CH) Permissible Brackish B1 1 Doubtful Brackish-salt B2 9 Unsuitable > Salt B3 4 Hyperhaline > Correlation analysis for the groundwater samples are presented in Table 5.7. Good correlation is obtained between Ca Cl, Mg and Na, Cl - Mg and Na, K - PO 4 and Mg - Na. Poor correlation exhibits between HCO 3 and CO 3 with other ions. Major ion contributing chemistry of groundwater in the study area is Cl, Ca, Mg and Na due to the positive correlation in the groundwater. Table 7: Correlation analysis Factor analysis was carried out and the results (Table 5.8) reflect the complexity in chemistry. Five factors were extracted with 80% of Total Data Variability (TDV). Factor 1 represented 1857

10 with 28% of TDV by Ca, Cl, Mg and Na indicating leaching of secondary salts. Factor 2 represented with 17% of TDV by HCO 3, K and PO 4 indicating weathering and anthropogenic impact. Factor 3 represented with 13% of TDV by CO 3 and ph due to ion exchange. Factor 4 represented with H 4 SiO 4 and HCO 3 indicates dissolution of silicate minerals and factor 5 represented with 9% of TDV by SO 4 indicates anthropogenic impact from nearby industries. Table 8: Factor analysis CA CL CO HCO K MG NA PH PO SI SO Total % of Variance Cumulative % Figure 2: Piper Trilinear plot 1858

11 Figure 3: Spatial distribution of EC Figure 4: USSL diagram 1859

12 Figure 5: Doneen Plot Figure 6: Thermodynamic stability for K-system 1860

13 Figure 7: Results obtained from the experiements 6. Conclusions The Electrical conductivity of the study area shows that it varies from 369 to 4109 μs/cm. But, most of the groundwater samples have EC higher than 1000 μs/cm. Sodium is the dominant cation and Chloride is the dominant anion in the study area. Based on hardness, the groundwater samples are moderately hard to very hard in nature. Based on the water quality standards, all the ions are present within the permissible limits except in EC and calcium. The quality of the groundwater is verified with WHO standards, which shows most of the groundwater samples are well within the suitable drinking purposes. The groundwater nature is explained by the Piper Trilinear diagram, which indicates that most of the groundwater samples come under Na-Cl type. Geochemical processes of the study area is explained by 1861

14 Gibbs plot and identified rock water interaction, which is the major process controlling the groundwater chemistry of the study area. The quality of the water for irrigation was estimated by USSL classification and Na%, indicates that all the samples range from good to permissible levels. In Doneen plot, most of the samples fall in class I indicates water is fit for irrigation purpose. The spatial distribution of EC shows that higher concentration was observed in the northern part of the study area indicates leaching of secondary salts. The corrosivity ratio indicates majority of samples fall in safe category.in thermodynamic stability diagram, most of the groundwater samples stable with Kaolinite field with minor representation in Montmorllinite field indicates excess supply of silica and cations.the statistical analysis of the hydrogeochemical data shows good correlation between Ca Cl, Mg and Na, Cl - Mg and Na, K - PO4 and Mg - Na. Factor analysis has identified five major factors responsible for water chemistry of the region. This reveals secondary leaching and anthropogenic impacts are the major controlling factors in the study area.saturation index of different form of carbonate is in the following order Aragonite > Calcite > Dolomite > Magnasite.The saturation index of groundwater with respect different form of silica reveals that cristobalite > chalcedony > amorphous. 7. References 1. Anandhan. P, Ramanathan, Chidambaram S, Manivannan R, Ganesh N, Srinivasamoorthy K, (2000), A study on the seasonal variation in the geochemistry of the groundwaters in and around Neyveli region, Tamilnadu. In: Proceedings of International seminar on applied hydro geochemistry, Annamalai University, pp CGWB, (1993), Report of the working group on the estimation of ground resources and irrigation potential of Periyar district, Tamil Nadu (Unpublished Report). 3. Doneen LD., (1948), The quality of irrigation water, California Agriculture Dept, 4(11), pp Gibbs RJ, (1970), Mechanisms controlling World s water chemistry, Science 170, pp Hegde SN, Puranik SCA., (1997), Nitrate pollution in groundwater, Hubli City, Karnataka, India. Workshop on Water-Pollution-Assessment and Management, Hyderabad, India, pp Johnson JH, (1975), Hydrochemistry in groundwater exploration-groundwater Symposisium Bulawayo. 7. Lakshmanan AR, Krishna Rao T, Viswanathan S, (1986), Nitrate and fluoride level in drinking waters of Hyderabad, Indian Journal of Environmental Health, 28(1), pp Lawrence, JF, Balasubramanian, A, (1994), Groundwater conditions and disposition of salt-fresh water interface in the Rameswaram island, Tamil nadu. 1862

15 Regional workshop on Environ Aspects of Groundwater dev. Oct , Kuruhshetra, India, pp Moody DW, (1990), Groundwater contamination in the united state. J soil and water conservation 41, pp Srinivasamoorthy, K., Chidambaram, S., Anandhan, P. and Vasudevan, (2005), Application of statistical analysis of the hydrogeochemical study of groundwater in hard rock terrain, Salem District, Tamilnadu, Journal of geochemistry, 20, pp USSL,(1954), Diagnosis and improvement of Saline and Alkali soils, USDA Handbook 60: Walton, KC., (1970), Groundwater resource evaluation. McGraw-Hill New York. 13. WHO, (1971), International standards for drinking water 3 rd edition Geneva, 70p 14. WILCOX LV, (1955), Classification and use of irrigation water. U.S. Geological Department Agricultural Circle 969, pp