Quality of water resources in the Bandalamottu area of Guntur District of Andhra Pradesh in South India is facing a serious challenge due to Pb mining. Therefore, 40 groundwater samples were collected from this area to assess their hydrogeochemistry and suitability for irrigation purposes. The groundwater samples were analyzed for distribution of chemical elements Ca 2? , Mg 2? , Na ? , K ? , HCO 3-, CO 3 2-, F-, Cl-, and SO 4 2-. It also includes pH, electrical conductivity, total hardness, non-carbonate hardness and total alkalinity. The parameters, such as sodium absorption ratio (SAR), adjusted SAR, sodium percentage, potential salinity, residual sodium carbonate, non-carbonate hardness, Kelly's ratio, magnesium ratio, permeability index, indices of base exchange (IBE) and Gibbs ratio were also calculated. The major hydrochemical facieses were Ca-HCO 3 , Ca-Na-HCO 3 and Ca-Mg-Cl types. The result of saturation index calculated by Visual MINTEQ software combined with Gibbs diagram and IBE findings indicate that, dolomite and calcite dissolution and reverse ion exchange can be a major process controlling the water chemistry in the study area. The results also showed that the salinity (85 %, C3 class) and alkalinity due to high concentration of HCO 3 and CO 3 and low Ca:Mg molar ratio (97.5 %, \1), are the major problems with water for irrigation usage. As a result, the quality of the groundwater is not suitable for sustainable crop production and soil health without appropriate remediation.

In the management of water resources, quality of water is just as important as its quantity. The main aim of this study has been to assess the variability of groundwater parameters to develop water quality of Tirupati area and its suitability for domestic and irrigation purpose. Further, the samples were analyzed for pH, EC, TDS, carbonates, bicarbonates, alkalinity, chlorides, sulfates, hardness, fluoride, calcium, magnesium, sodium, and potassium. Based on the analytical results, chemical indices like percent sodium, sodium absorption ratio (SAR), adjusted SAR, percent sodium (Na %), residual sodium carbonate (RSC) and permeability index (PI) have been calculated. Chadha rectangular diagram for geochemical classification and hydrochemical processes of groundwater indicated that most of waters are Ca-Mg-HCO 3 and Ca-Mg-Cl types. Assessment of water samples from various methods indicated that majority of the water samples are suitable for domestic and irrigation purpose.

The groundwater samples from Rapur area were collected from different sites to evaluate the major ion chemistry. The large number of data can lead to difficulties in the integration, interpretation, and representation of the results. Two multivariate statistical methods, hierarchical cluster analysis (HCA) and factor analysis (FA), were applied to evaluate their usefulness to classify and identify geochemical processes controlling groundwater geochemistry. Four statistically significant clusters were obtained from 30 sampling stations. This has resulted two important clusters viz., cluster 1 (pH, Si, CO 3 , Mg, SO 4 , Ca, K, HCO 3 , alkalinity, Na, Na ? K, Cl, and hardness) and cluster 2 (EC and TDS) which are released to the study area from different sources. The application of different multivariate statistical techniques, such as principal component analysis (PCA), assists in the interpretation of complex data matrices for a better understanding of water quality of a study area. From PCA, it is clear that the first factor (factor 1), accounted for 36.2% of the total variance, was high positive loading in EC, Mg, Cl, TDS, and hardness. Based on the PCA scores, four significant cluster groups of sampling locations were detected on the basis of similarity of their water quality.

Multivariate statistical techniques involving factor analysis (FA) and R-mode hierarchical cluster analysis (HCA) were performed on 30 groundwater samples from Rangampeta, Chittoor District, Andhra Pradesh, South India to extract principal processes controlling the water chemistry. The groundwater samples were analyzed for distribution of chemical elements Ca, Mg, Na, K, Si, HCO 3 , CO 3 , Cl, and SO 4 . It also includes pH, and electrical conductivity (EC). Gibbs diagrams were also constructed to identify the processes that are responsible in controlling the water chemistry. Factor analysis extracted for four factors consisting of F1 (with high loading factor of Cl, EC, Mg and Na), F2 (with high loading factor of K, (HCO 3 +CO 3 ) and Ca), F3 (with high loading factor of pH and Si) and F4 (with high loading factor of SO 4 ). The varifactors obtained from Factor analysis indicated that the parameters responsible for groundwater quality variations are mainly related to groundwater-rock interaction (particularly weathering of silicate minerals), agriculture and anthropogenic sources. With HC analysis the water samples have been classified into 4 clusters. Cluster I (13 wells) and cluster II (8 wells) have shown moderate salinity. However, cluster IV (4 wells) had the lowest concentrations of ions and classified as fresh water. Cluster III (5 wells) shows mid salinity between (I and II) and IV clusters. The distribution of these groundwater types and their quality has been found to be an in direct relation with the host rocks of the area. The results showed that the method was comprehensive and efficient in analyzing the dynamics of water quality.

A detailed survey showed that groundwater fluoride was 6.1ppm in the Talupula area of the Anantapur district in southern India which is higher than is normally observed in groundwater elsewhere in India but not so extreme as that reported in Andhra Pradesh (up to 21 mg L−1). Groundwater is used for irrigating agricultural crops as well as for drinking which may expose its population to higher concentrations of fluoride through their diet. A preliminary study examined the concentrations of fluoride in five agricultural crops in the Talupula area and the soil beneath agricultural crops. The stem and leaves of Heliathusannuas, Arachishypogaea, Morusalba, Lychopersiconesculantum, and Phaseolus vulgaris were examined for fluoride and heavy metal accumulation. Heavy metal (Zn, Cu and Pb) accumulation in the stem and leaves were examined to determine if there was any correlation between their uptake and that of fluoride. In the soil beneath the crops, fluoride concentrations ranged from 6.53±0.44 to 8.23±1.22 ppm and a significant accumulation of fluoride was observed in the stems (13.2±2.0 to 23.9±3.6 ppm; p < 0.001) and leaves (16.4±1.9 to 61.5±4.5 ppm) of the agricultural plants. A significant accumulation of fluoride was observed from the stem to the leaves for all plants (p < 0.03) except Helianthus annuas. Copper also displayed significant accumulation from the soil to the stems in some of the plants tested but there was no significant accumulation of zinc or lead. A significant translocation from the stem and accumulation in the leaves was not observed for Cu or Pb but there was significantly higher zinc in the leaves of Arachishypogaea and Morusalba when compared to their stems. This study demonstrated that agricultural plants grown under field conditions and irrigated with groundwater high in fluoride will accumulate fluoride, but that fluoride is unlikely to have a significant effect on Cu, Zn or Pb accumulation in the stems and leaves of agricultural plants of the area. While drinking water is still the major cause of fluorosis in southern India, consumption of foods with high fluoride concentrations may also increase the risk of fluorosis.