By definition pH is the negative logarithm of the hydrogen ion concentration of a solution and it is thus a measure of whether the liquid is acid or alkaline. The pH scale (derived from the ionisation constant of water) ranges from 0 (very acid) to 14 (very alkaline). The range of natural pH in fresh waters extends from around 4.5, for acid, peaty upland waters, to over 10.0 in waters where there is intense photosynthetic activity by algae. However, the most frequently encountered range is 6.5-8.0. pH level above 8.0, there is progressive decrease in the efficiency of the chlorine disinfection process. The pH of different aquatic ecosystems determines the health and biological characteristics of those systems. Thus, the increasing or decreasing range of pH creates bad impact on health due to increasing saline or basic effect of pH value. One of the main objectives in controlling the pH is to minimize corrosion and incrustation in the distribution system, which results from the complex relationship between pH and other constituents or characteristics, such as lead, may results from the corrosion of specific types of pipe, and the rate of corrosion increases with decrease in the efficiency of the chlorine disinfection process. There is a non-significant main effect of region on the pH values of the water samples collected. It indicates that pH value of water is not significantly different in both the regions.Figure 2 also depicts that pH of Vindhyan plateau is higher than Alluvial Ganga plains, showing high level of salinity. Results indicate that this difference is only due to region wise change. There is a significant difference in the main effects on the pH values of water samples collected from different sources and various seasons wise. Previous it is being discussed that change in ground and surface water is due to other anthropogenic factors. No doubt pH value of summer season is high among all seasons as there is less percolation of fresh water Figure 2.

Cool water is generally more palatable. Low water temperature tends to decrease the efficiency of treatment processes, including disinfection, and may thus have a deleterious effect on drinking water quality. However, high water temperature enhances the growth of micro organisms, and taste, odour, colour and corrosion problem may be increased. There is a non-significant main effect of region as well as seasons on the EC values of the water samples collected. It indicates that EC value of water is not significantly different in both the regions wise as well as different source wise. Results indicate that again change in region is the dominant cause of variationFigure 3. Besides that EC value of surface water is very high because as intermixing of fresh water is more incomparison to ground water. Although EC value of summer season of Alluvial Ganga plain is much higher in comparison to samples of Vindhyan plateau Table 3. But there is a significant difference in the main effects on the EC values of water samples collected from different seasons.

Figure 3

Total dissolved solids consist mainly of inorganic substances. The principal constituents of TDS are calcium, magnesium, sodium, bicarbonate, chlorides, and sulphates. An important aspect of TDS, with respect to drinking water quality, is the effect on taste. The palatability of water with TDS level of less than 500 mg/litre is generally considered to be good (Table 4). Thus, the TDS value of Mirzapur District is crossing the permissible limit, which is alarming in nature. TDS value of water is not significantly different in both the regions. But results indicates that there is a significant difference in the main effects on the TDS values of water samples collected from different sources and as per the various seasons wise. Results indicates that TDS value of surface water is very high which is due to anthropogenic changes of water Figure 4 and Table 4.

Figure 4

The increasing or decreasing range of pH creates bad impact on health due to increasing saline or basic effect of pH value. One of the main objectives in controlling the pH is to minimize corrosion and accumulation in the distribution system, which results from the complex relationship between pH and other constituents or characteristics, such as lead, may results from the corrosion of specific types of pipe, and the rate of corrosion increases with decrease in the efficiency of the chlorine disinfection process. pH of Vindhyan plateau is higher than Alluvial Ganga plains, showing high level of salinity. Low water temperature tends to decrease the efficiency of treatment processes, including disinfection, and may thus have a deleterious effect on drinking water quality and pH value of Mirzapur district is very alkaline by nature. In the same way, total dissolved solids consist mainly of inorganic substances. The TDS value of Mirzapur District is crossing the permissible limit, which is alarming by nature. Results indicate that TDS value of surface water is very high which is due to anthropogenic changes of water.

The Hydrogeochemical composition ranges of collected ground waters of the study area in the August 2012, January 2013 and June 2013, and it’s shown in the Table 5.

In general, pH of the waters is alkaline in nature. The pH is controlled by total alkalinity of the ground water and partially of sea water. pH of water sample in during the year 2013 in summer varies from 7.23 to 8.64 with an average of 7.88, while during monsoon samples varies from 7.03 to 7.70 with an average of 7.47, and in the winter 2013 it varies from 6.63 to 8.07 with an average of 7.27. pH is dominating in the study area during summer 2013 (June) and winter 2013 (January) seasons. The high pH in certain location might be due to the natural salinity presents and it mixing with fresh water.

The measure of conductivity is directly proportional to the strength of the water. Higher values of EC and TDS are represented in the summer 2013 and winter 2013. They indicate that dissolution of infiltrating rain water and over exploration of ground water for domestic and agriculture purposes. In the study area, EC of water samples during the year of 2013 in summer it varies from 205 µs/cm to 1730 µs/cm with an average of 722 µs/cm, while in the monsoon samples it ranges between 133 µs/cm to 566 µs/cm with an average of 349 µs/cm, and in the winter 2013 samples it ranges from 191 µs/cm to 1817 µs/cm with an average of 734 µs/cm. In the present study, higher EC values are observed in winter and summer during 2013 it indicate the more industrial influence to contaminate the ground water potential in this area. The TDS of water samples during the year of 2012 and 2013, 416 mg/l to 872 mg/l in August 2012 and 392 mg/l to 1592 in June 2013. In January 2013 varies from 413 mg/L to 1307 mg/L. The TDS values are relatively higher during January 2013 and followed by June 2013.

Table 5, Table 6, Table 7 shows the correlation matrix and its significance levels for all the observed data. Because all the sampling stations were combined in order to calculate the matrix, the correlation coefficients should be interpreted with caution as they are affected simultaneously by spatial and temporal variations. Nevertheless, some physio-chemical relationships can be inferred. The chemistry of water is influenced by the input of materials their solubility and the chemical equilibrium prevailing in the aqueous solution. For the effective management of water quality through appropriate control measures one needed continuous monitoring of water quality about different physio-chemical parameters of water. January 2013 shows absence of correlation among Ph-TDS and EC. In year August 2012,shows good correlation with TDS-EC, EC-TDS. June 2013, shows good correlation with EC-pH, TDS-pH, TDS-EC (Table 8 ).

pH stands for “potential of hydrogen” referring to the amount of hydrogen found in a substance (in this case, water). pH is measured on a scale that runs from 0 to 14. Seven is neutral, meaning there is a balance between acid and alkalinity. Water with a low pH can be acidic, naturally soft and corrosive. Acidic water can leach metals from pipes and fixtures, such as copper, lead and zinc. It can also damage metal pipes and cause aesthetic problems, such as a metallic or sour taste, laundry staining or blue-green stains in sinks and drains. Water with a low pH may contain metals in addition to the before-mentioned copper, lead and zinc. Drinking water with a pH level above 8.5 indicates that a high level of alkalinity minerals are present. High alkalinity does not pose a health risk, but can cause aesthetic problems, such as an alkali taste to the water that makes coffee taste bitter; scale build-up in plumbing; and lowered efficiency of electric water heaters 5.

TDS in water supplies originate from natural sources, sewage, urban and agricultural run-off, and industrial wastewater. Salts used for road de-icing can also contribute to the TDS loading of water supplies. No recent data on health effects associated with the ingestion of TDS in drinking-water appear to exist; however, associations between various health effects and hardness, rather than TDS content, have been investigated in many studies.

As per the analysis pH of Vindhyan plateau is higher than Alluvial plains. Wells are the basic source of drinking water resource since long time. But deteriorating water level is the major problem. As per the primary survey now district administration is providing water through piped water supply by accumulating water in tanks. But in most of the remote villages of Blocks of Vindhyan plateau such as Hallia, Lalganj and Rajgarh blocks these facilities are still needed. Thus, by developing piped water system dependency on surface water will also decline and ground water sustainability will remain under limits.

There is variation in the hydro-geochemical composition of the collected ground waters of the study area during rainy (2012), summer (2013) and winter (2013) season. So far as geo composition of ground water is considered, in general pH of the waters is alkaline in nature. The high pH in certain location might be due to the natural salinity presents and it mixing with fresh water. Higher EC values during summer (2013) and winter (2013) indicate the more industrial influence to contaminate the ground water potential in this area.