International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 05 | Aug-2015 www.irjet.net p-ISSN: 2395-0072 CHEMICAL CHARACTERISTICS AND GROUNDWATER QUALITY ASSESSMENT IN MANGALORE BLOCK, CUDDALORE DISTRICT, TAMIL NADU, INDIA. Senthil Kumar, G.R. 1, NSENGIMANA Serge 2, UWAMUNGU Placide 3 1 Associate Professor, Department of Earth Sciences, Annamalai University, Tamil Nadu, India 2 PG Student, Department of Earth Sciences, Annamalai University, Tamil Nadu, India 3 PG Student, Department of Earth Sciences, Annamalai University, Tamil Nadu, India ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract - Groundwater is the prime source of drinking adopted for the hydrochemical facies classification using the water supply for many of the Indian rural and urban criteria of Schoeller, Stuyfzand and USSL schemes, etc. habitats. Water quality plays an important role in According to Sawyer and MC Carthy around 61% of area is promoting agricultural production and standard of human covered by very hard water and hard water. Based on health. Study on chemical characteristics of groundwater Schoeller’s water type, the type III water dominates the and influence on human health is necessary to study in every area. The Stuyfzand classification reveals that fresh brackish part of the country. An elaborate hydrogeochemical study water dominates in the study area. The USSL classification was carried in Mangalore Block, Cuddalore District, Tamil exhibits that C3S2 category for 49%, which indicates high Nadu. The present study mainly focused on chemical salinity-medium sodium water occupies half of the study characteristics of groundwater with respect to the area. Non corrosive water covers around 75%. Gibbs plot hydrogeochemical facies, genetic geochemical evolution of reveals that evaporation process is more dominating than groundwater, and hydrogeochemical signatures. Thirty nine rock water interaction. The overall studies indicate that the groundwater samples were collected from dug wells and groundwater quality in the study area is not encouraging hand pumps during pre monsoon season (2014). These for drinking and other purposes. Further to develop the water samples were analysed for major cations and anions. quality and quantity of groundwater in the study area, a The water analysis data was processed using a computer detailed scientific study including rejuvenation of surface programme HYCH. In this program, numerical steps are water resources is necessary for groundwater development. 1. INTRODUCTION through which the water flows, depending upon the mineral dissolution, mineral solubility, ion exchange, Having a safe drinking water is an internationally oxidation, reduction, etc., [4]. Water quality is a term accepted human right [1] Groundwater is the prime used to describe the chemical, physical and biological source of drinking water supply for many of the Indian characteristics of water, usually in respect to its rural and urban habitats, like in other parts of the world suitability for a particular purpose [5]; [6]. Researchers [2]. Due to inadequate supply of surface water, demand show that the hydrogeochemical characteristics of for groundwater resource has increased in many folds in groundwater and groundwater quality in different recent times for drinking, irrigation, and industrial aquifers over space and time are important parameters purposes in the world. It is estimated that approximately in solving the groundwater management issues [7]; [8]; one third of the world’s population use groundwater for [9]; [10]; [11]. The problems of groundwater quality are drinking [3]. Because of the over-exploitation of more acute in areas of which dense populated and thick groundwater, it has detrimentally affected its quantity industrialized area have shallow groundwater tube wells and quality. The chemical quality of groundwater can [12]. In hard rock terrain, availability of groundwater is influence the chemical composition of soils and rocks limited and its occurrence is essentially confined © 2015, IRJET ISO 9001:2008 Certified Journal Page 950 International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 05 | Aug-2015 www.irjet.net p-ISSN: 2395-0072 to fractures and weathered zones [13]. At the start, it intermediate to acid in composition, coarse to medium should be pointed out that the quality of groundwater grained and form the high land topography. The depends on the chemical composition of recharge water, charnockitic rocks are massive to foliated and the the interaction between water and soil, soil–gas foliations usually trending ENE – WSW with an average interaction, the types of rock with which it comes into dip of 45° towards South. The charnockite shows contact in the unsaturated zone, the residence time of different depth of weathered zones. In the study area groundwater in the subsurface environment and the groundwater occurs under water table conditions in the reactions that take place within the aquifer [14]; [15]; joints, fractures and weathered rocks. Generally the [16]. The present study mainly focused on chemical charnockite of the study area is highly massive and characteristics of groundwater with respect to the compact and devoid of joints and fractures making it hydrogeochemical facies, genetic geochemical evolution impervious, which in turn result in poor potential. of groundwater, and hydrogeochemical signatures. [17]. 4. MATERIALS AND METHODS 2. STUDY AREA The study area falls in Mangalore Block of Cuddalore The groundwater in the study area has been classified District, Tamil Nadu, South India (location map shown in using various geochemical parameters in the following Fig. 1). The study area lies between the latitudes North manner. In order to cover the entire study area, thirty 11°21’80” to 11°30’11” and the longitudes East 78°40’57” nine groundwater samples were collected during the pre- to 79°03’11” in the Survey of India Toposheet numbers monsoon period (July 2014). The location’s coordinates were recorded with GPS receiver. The Electrical 58 & 58 . The study area covers about 100 sq. km; Conductivity (EC) and pH were measure immediately on the relief ranging from 62 to 121 m above MSL. The collection of water samples in the field using portable average annual rainfall is about 1100 mm, of which more consort C-425 digital pH meter. The collected samples than 80% is received during NE monsoon. The were chemically analysed by standard analytical method. temperature of the study area ranges from 20° C in the [19] at Tamil Nadu Water and Drainage, (TWAD), month of January to 34°C in the month of May. The river Cuddarole. The analytical results have been processed by Vellar flows in the southern part of the study area which using a computer program HYCH [20]. This program is originates in shevroy hills and finally joins in the Bay of capable of providing most of the needed output using the Bengal. The drainage pattern is of mostly dendritic. The major ion chemistry data. It aids in the interpretation of geomorphology of the area consists of the old flood water quality based on water chemistry, facies, plains, pediments, duricrust and covered by forest land. mechanisms of origin, type, suitability and usage factors [18]. like corrosivity and permeability. HYCH Program data processing flow chart is shown in Figure 2. with the output result. GIS technique has been used for preparation of thematic maps and the following maps have been generated and discussed in detail. i) Total Dissolved Solids, ii) Total Hardness, iii) Schoeller water type Classification, iv) Stuyzand water Classification, v) USSL Classification, vi) Corrosivity ratio and vii) Gibbs plot. Fig-1: Location map of the study area 3. GEOLOGICAL SETTING The study area rock types belong to early to mid Precambrian period represented by charnockite and charnockitic gneiss, indicating the oldest and subjected to granulite facies of metamorphism. The charnockites are © 2015, IRJET ISO 9001:2008 Certified Journal Page 951 International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 02 Issue: 05 | Aug-2015 www.irjet.net p-ISSN: 2395-0072 Dissolved Solids present in groundwater. According to his classification TDS up to 100 mg/l is fresh water, 1,000- 10,000 mg/l is brackish water, above 10,000 mg/l is saline water and above 1,00,000 is brine water. TDS of the study area ranges from 378 mg/l at Thachchur (Location No.23) to 3640 mg/l at Pudukulam (Location No. 25). The pre- monsoon period aquifer exhibits that the TDS values less than 1000 mg/l which is about 51% of the study area falls in fresh water category, TDS values between 1000-1500 mg/l falls in 11 locations (28 %) near to fresh water category. The remaining 21 % samples falls in brackish category according to Carroll's classification. Fresh water (TDS<1000 mg/l) occurs a half of the study area during pre-monsoon period. Region around Pudukulam (Location No. 25) is found to be having groundwater with high TDS Fig-2: Flow chart shows HYCH program hydrochemical above 3000 mg/l, which indicates that the location having data processing method. effluent. Groundwater of moderate quality occurs in the rest of the study area. High concentration of TDS has been 5. RESULTS AND DISCUSSION added on the rainwater through interactions with soils and rocks [23]. During the slow movement of groundwater in subsurface the TDS concentration is slowly enriched. The study area pre-monsoon groundwater characteristics Groundwater has low TDS in recharge areas than in are shown in Table 1. The computer software HYCH discharge areas [14]. processed output data of the study area for pre-monsoon groundwater is shown in Table 2. 5.1. pH and EC The various physico-chemical parameters of ground water sample of Mangalore block are present in table 1. The pH value of pre-monsoon groundwater samples varies from 6.8 to 8.3 with an average of 7.45. However the pH falls in the recommended limit (6.5 to 8.5) for human consumption.