Evaluation of Groundwater Quality for Suitability of Irrigation Purposes: A Case Study in the Udham Singh Nagar, Uttarakhand

In the present study, the groundwater quality for suitability in agriculture from Udham Singh Nagar district, Uttarakhand, has been evaluated. A total of 50 groundwater samples have been collected and analysed for pH, EC, TH, HCO3−, CO3, Cl, SO4, NO3, Ca, Mg, Na and K. To assess the groundwater quality for irrigation purpose, parameters like sodium adsorption ratio (SAR), soluble sodium percentage (SSP), residual sodium carbonate (RSC), magnesium hazards (MHs), permeability index (PI), and chloroalkaline index (CAI) values have been calculated. In USSL diagram, most of the groundwater samples fall in the C2S1 category and were safe for irrigation purpose. Only seven groundwater samples fall in the C3S1 category, indicating medium to high salinity which is safe for irrigation purpose for all types of soils but with limited care of exchangeable sodium. On the basis of RSC, all groundwater samples were observed to be suitable for irrigation purpose. Piper diagram indicated that 50% of the groundwater samples belonged to the Mg-Ca-HCO3 type and 48% was classified as the Ca-Mg-Cl type. Durov diagram suggested possibilities of ion mixing and simple dissolution of ions from polluted soil.


Introduction
Groundwater plays an important role all over the world for the survival of both flora and fauna. India is one of the largest users of groundwater, particularly for drinking and agriculture purposes [1] Agriculture is one of the most important sectors of Indian economy. In rural areas, the major sources of groundwater for drinking and irrigation purpose are hand pump and tub well. According to a national sample survey, 56% households get drinking water from hand pump or tube well, 14% from open well, and 25% based on piped water [2]. Groundwater gets contaminated with a variety of pollutants such as domestic, agriculture, and industrial due to utilization of fertilizers, pesticides, and other chemical products [3]. e groundwater quality assessment based on different agriculture indices has been studied in different parts of world [4,5].
To the best of our knowledge, no study on the assessment of irrigation water quality has been undertaken from Udham Singh Nagar District of Uttarakhand with especial reference to dug well and hand pump water. erefore, in the present study, an attempt has been made to determine the groundwater suitability for irrigation purpose from Udham Singh Nagar district of Uttarakhand. longitudes 78°45′N and 80°08′N. e district Udham Singh Nagar covers Champawat and Nainital district in North region of Uttarakhand, south region with Pilibhit, Moradabad, and Bareilly district of UP, and Biznor district of UP on the west and Nepal on the east.

Collection of Samples.
Fifty groundwater samples (hand pump and dug well) were collected in premonsoon season in the year 2018 from different sites of Khatima, Bazpur, Gadarpur, Kashipur, Jaspur Kicha, and Sitarganj blocks of Udham Singh Nagar district, Uttarakhand (Table 1; Figure 1). e samples were collected in prewashed polyethylene narrow mouth bottles (three times rinsed with same water to be sampled). Locations (longitude, latitude, and altitude) of sampling point were measured by using a global positioning system (GPS).

Chemical
Parameters of the Samples. Electrical conductivity (EC) and pH were measured using a potable kit. e water samples were filtered with using 0.45 Millipore membrane filter paper for the separation of suspended solids. Sulphate (SO 4 2− ) content was determined by the UV spectrophotometric method, while chloride (Cl − ) and bicarbonate (HCO 3 − ) content were measured by the titration method [22]. e detection of Ca 2+ , Mg 2+ , and total hardness (TH) was done by the titration method, while Na + and K + were estimated by the flame photometer method [22].

Evaluation of Irrigation Water Quality.
e concentrations of different parameters were interrelated, and irrigation indexes like soluble sodium percentage (SSP), sodium adsorption ratio (SAR), residual sodium carbonate (RSC), magnesium hazard (MH), permeability index (PI), and chloroalkaline index (CAI) were calculated to assess groundwater quality. USSL salinity, Wilcox, permeability index, and Gibbs diagrams were drawn with the help of Grapher free software to assess irrigation quality of collected water samples. Hydrochemical analysis was evaluated by drawing Piper and Durov diagrams using Aquachem (2004) software.

Salinity and Alkalinity Hazard (SAH).
Electrical conductivity and US Salinity Laboratory diagram helped in explaining salinity and alkalinity hazard in the study area. (SH). Sodium hazard was assessed by evaluating soluble sodium percentage and sodium absorption ratio and drawing Wilcox diagram.

Soluble Sodium Percentage (SSP).
Soluble sodium percentage (SSP) was calculated by employing the equation given by Todd [23]. e ionic concentration was presented in meq L −1 : (1)

Sodium Adsorption Ratio (SAR)
. SAR was calculated using the equation given by Raghunath [24]. e concentration of the ions was expressed in meq L −1 : (2)

Carbonate and Bicarbonate Hazard (CBH).
Carbonate and bicarbonate hazard was assessed by evaluating soluble sodium carbonate.

Residual Sodium Carbonate (RSC).
is was evaluated employing the following equation of Eaton [25]:

Magnesium Hazard (MH).
is was evaluated by the equation given by Szabolcs and Darab [26], where the concentration of each cation was expressed in meq L −1 : 2.6. Permeability Index (PI). Permeability index (PI) was used to classify the irrigation water quality and was calculated by the formula given by Doneen [27]. e concentration of all ions was taken in meq L −1 : 2.7. Chloroalkaline Index (CAI). Chloroalkaline index (CAI I and CAI II) was calculated by the formula given by Scholler [28]:

Results and Discussion
3.1. pH. e term pH expressed to describe the intensity of acidic and alkaline nature of a solution. e pH value of the groundwater samples in the study area lie in between 7.57 and 8.61. All the groundwater samples belonged to the safe limit for irrigation purpose [29].

Water Quality Based on the Absolute Ions.
In the present study area, the concentration of cations lies from 20.0 to 140.0 mg L −1 for Ca 2+ , 14.1 to 85.0 mg L −1 for Mg 2+ , 0.4 to 62.0 mg L −1 for Na + , and 0.0 to 55.2 mg L −1 for K + (Table 2). In irrigation water, the permissible limit for Ca 2+ , Mg 2+ , Na + , and K + is 80, 35,200, and 30 mg L −1 , respectively [30,31]. On the basis of these permissible limits, 96% groundwater samples for Ca 2+ , 42% for Mg 2+ , 100% for Na + , and 100% for K + were fit for irrigation purpose. e permissible limit for anions HCO 3 − and Cl − is 250 mg L −1 [30,31]. e values of HCO 3 − and Cl − in the groundwater samples varied from 29.2 to 372.0 mg L −1 and 8.2 to 252.4 mg L −1 , respectively (Table 2). e results on major anions revealed that 64% water samples as per the limit of HCO 3 − and 98% as per the limit of Cl − were observed to be fit for irrigation purpose. (TH). In water quality, TH is an important parameter whether it has been used for domestic,   Journal of Chemistry CaSO 4 is formed. e major source of Mg in groundwater is dolomite, CaMg(CO 3 ) 2 . According to Sawyer and McCarthy (1967) [32], water can be categorized as soft (>75 mg L −1 ), moderately hard (75 to 150 mg L −1 ), hard (150 to 300 mg L −1 ), and very hard (above 300 mg L −1 ). In the present study, TH varied from 155 to 539 mg L −1 , indicating hard to very hard nature of water. irty-nine samples had hard category, while 20% samples (11 samples) had hardness higher than 300 mg L −1 , which is a desirable limit for drinking purpose ( Table 2).

Salinity and Alkalinity Hazard (SAH).
e groundwater becomes saline if high salt content is present. e evaluation of salinity hazard is an important parameter of agriculture water as high salt content of irrigation water causes the soil to become saline, and it also adversely affects the salt intake efficiency of the plants. Electrical conductivity (EC) and total dissolved solid (TDS) values are measure of salinity hazard of irrigation water. In the present study, the values of EC and TDS ranged from 353 to 1274 µS -1 cm −1 and 229 to 828 mg L −1 , respectively ( Table 2). According to the limiting value [33] of TDS for water suitability for irrigation purpose, 28% groundwater samples belonged to the moderate category. Furthermore, the classification and distribution of groundwater samples with respect to salinity (EC) is given in Table 3. e water samples were classified into four groups on the basis of salinity [34]. Irrigation water quality based on salinity indicated that no water sample belonged to the excellent category (C1). Eighty-six percent of the samples belonged to the C2 class, and remaining 14% was found in the C3 class. On the basis of salinity, none of the samples were observed to be unfit for irrigation purpose.

United States Salinity Laboratory (USSL) Diagram.
USSL diagram has been used to study the quality of groundwater suitability for irrigation purpose [35]. e SAR and EC values of water samples of Udham Singh Nagar District were plotted in the graphical representation (Figure 2) and found that 43 samples fall in C2S1 (medium salinity with low sodium category) and remaining 7 samples fall in C3S1 (high salinity and low sodium category). C3S1type water cannot be used on soil with restricted drainage. Bhandari and Joshi (2013) reported that 98% of spring water samples from Almora district of Uttarakhand fall in C1S1, which indicated suitability of these samples for irrigation purpose [36].

Wilcox Diagram.
Wilcox diagram is plotted for classification of water for irrigation suitability [37]. In this diagram, the EC was plotted against the percentage of Na. According to Wilcox classification, 86% of the water samples belonged to the excellent good category and remaining 14% groundwater samples fall in good category ( Figure 3). Bahukhandi et al. [21] assessed ground and surface water quality of Hardwar district, Uttarakhand, and observed that, according to the US salinity diagram, most of the ground and surface water samples fall in C1S1 and C2S1 categories, while according to Wilcox diagram, large number of water samples was within excellent to good category [38].

Sodium Hazard (SH)
3.7.1. Sodium Adsorption Ratio (SAR). According to Gholami and Srikantaswamy [39], the alkali or sodium hazard can be expressed in terms of sodium adsorption ratio. Sodium hazard is the main parameter for assessment of groundwater suitability for irrigation purpose. Sodiumenriched groundwater is unsuitable for irrigation of agricultural lands. Biswas et al. [40] reported that excess sodium in water produces undesirable effect of changing soil permeability and water infiltration due to breakdown in the physical structure of the soil. In a previous study, the SAR values ranging from 0 to 10 were measured as excellent, 10-18 were measured as good, and values greater than 18 were measured as unsuitable for irrigation purpose [41]. In the present study, the SAR values ranged between 0.01 and 1.49 and, thus, were classified as the S1 level, which belonged to an excellent category for irrigation purpose (Table 4). Shahidullah et al. reported groundwater quality of Mymensingh district in Bangladesh and suggested that there was a linear relationship between sodium adsorption ratio (SAR) and soluble sodium percentage (SSP) and also observed that groundwater could be safely used for long-term irrigation purpose [42]. Dudeja et al. have also reported that the groundwater of Doon valley in outer Himalaya, Uttarakhand, had suitability for drinking and irrigation purpose [17]. Seth et al. studied that Kosi river water in Almora district, Uttarakhand, could not be used for drinking purpose, while it was found to be suitable for irrigation purpose on the basis of SAR, %Na, and RSC [20].

Soluble Sodium Percentage (SSP).
According to Nagarju et al., the percentage of soluble sodium is an important parameter in classifying irrigation water in terms of soil permeability [43]. Sodium ion present in irrigation water tends to be exchanged by Mg 2+ and Ca 2+ ions present in clay particles. is exchange process reduces the permeability of soil and causes poor internal drainage and hardening of soil, which further adversely affects the soil quality and seedling emergence [44]. Additionally, high levels of sodium encourage combination of sodium with chloride and carbonates generating salinity and alkalinity in soils. Excessive soil salinity and alkalinity are harmful for plant growth and crop productivity. e classification of irrigation water based on soluble sodium percentage (SSP) is given by Todd [45]. He classified the irrigation water quality into 5 categories (excellent, good, permissible, doubtful, and unsuitable). In the present study, the soluble sodium percentage varied from 0.3 to 35.4%, which suggested that all the groundwater samples had excellent to good quality for irrigation purpose (Table 4).

Residual Sodium Carbonate (RSC).
e quantity of carbonate and bicarbonate surplus to that of alkaline Earth Journal of Chemistry metal ions (Ca 2+ and Mg 2+ ) also influences the suitability of groundwater for irrigation purpose [37].
is surplus amount of carbonate and bicarbonate is called residual sodium carbonate (RSC). Higher RSC values indicate that much of the calcium and some magnesium ions get precipitated from the solution, and thus, the percentage of sodium increases in water and soil particles, which in turn increases the potential for sodium hazard. e RSC values of the collected water samples varied in between −4.92 and 0.72 meq L −1 . Based on the RSC values, all samples were found to be safe for agriculture purpose (Table 5).

Magnesium Hazard (MH).
In the natural water system, magnesium and calcium maintain a state of equilibrium. High value of any one of the cations can increase soil pH and  reduces infiltration capacity of soil, which adversely influences the crop yield. As the content of magnesium was found to be high in the collected samples, magnesium hazard was evaluated in this study. If the value of magnesium hazard is more than 50%, the soil becomes alkaline and its opposite impact on crop yield can be observed [46].
According to Khodapanah et al., the water samples with MH values higher than the 50 are unsuitable for irrigation [36]. In the present study, MH values varied from 32 to 81, which indicated that 56% samples had MH values more than 50. In the study area, the elevated amount of magnesium might be due to dissolution of dolomite. In a study from     Almora district [47], MH values of spring water varied from 0.39 to 38.37. Hence, these samples are observed to be unsuitable for irrigation (Table 4).

Permeability Index (PI).
On the basis of PI values, groundwater quality can be assessed for its suitability for irrigation purpose [48]. According to Singh et al., the concentration of Ca 2+ , Na + , Mg 2+ , and HCO 3 − influences permeability of soil profile [49]. erefore, these cations and anions are used to calculate PI values of water to evaluate its quality. Xu et al. correlated high PI values with high amount of sodium and bicarbonate ions in groundwater [50]. e high levels of HCO 3 − and Na + ions may be due the Nagaraju et al. classified water quality on the basis of PI into Classes I, II, and III. Classes I and II indicate good water quality for irrigation purpose (>75% and 25-75% permeability respectively), while Class III (up to 25% permeability) water is unsuitable for irrigation [43]. A high permeability index is associated with subsurface structural features, which facilitate widespread contamination of groundwater. As per the PI values, the groundwater samples of the study area fall in Classes II (29.05-72.75%) and were described as having excellent to good permeability [51] (Table 4 and Figure 4).

Spatial Distribution
Maps. Geographical information system (GIS) is the special tool which is used to create spatial distribution maps, indicating suitable and unsuitable zones based on water quality parameters [52]. In the present study, spatial distribution maps were drawn for EC, TH, SAR, SSP, MH, and PI. e spatial distribution map of EC is shown in Figure 5. is indicated that more than half of the study area was alkaline in nature. e spatial distribution map of TH suggested that central part of the study area had the high TH value ( Figure 6). SAR distribution map indicated that majority of the locations was within the excellent zone (SAR  Journal of Chemistry 0.5-1.0) (Figure 7). Figure 8 is the spatial distribution map of SSP. is map suggested that the SSP values of all the samples were excellent to good. e spatial distribution maps indicated that groundwater collected from the central part of the study area was rich in hardness and salinity along with some small patches in the western region. e spatial distribution map of MH is shown in Figure 9, which indicated that the eastern part of the study area is having very low MH values as compared to the western part of the study area. e spatial distribution map indicated that the western region of the study area had the highest PI value. Most of the study area showed permeability index in between 40 and 50% ( Figure 10).

Hydrochemistry
3.11.1. Piper and Durov Diagrams. Hydrochemical interpretation of the analysed samples has been attempted by plotting the data in the Piper and Durov [53] diagrams ( Figure 11). In the Piper diagram, analysed chemical data are plotted in two triangular fields, which are ultimately projected into an upper diamond-shaped field. Similar groundwater samples can be identified using this diagram as they are plotted as a cluster. e data plots in the Piper diagram suggested that 50% samples were the Mg 2+ -Ca 2+ -HCO 3 − type along with 48% Ca 2+ -Mg 2+ -Cl − type and only two water samples belonged to the Ca-Na-HCO 3 water type. e data plots in Piper diagram and Durov diagram revealed that cations were dominated by Mg 2+ followed by Ca 2+ and Na + , while anions were dominated by HCO 3 − , followed by Cl − and SO 4 2− (Figure 11). e results of the study were similar to the reports on hydrogeochemical analysis of groundwater samples from India [54] and South Africa [55], where they observed that the alkaline earth metals were the dominant metal ions in groundwater samples. High levels of calcium may present naturally, but the dominance of sodium and magnesium ions is due to their dissolution from polluted rocks and soils [56].
3.11.2. Chloroalkaline Index. Scholler observed the change in the chemical composition of groundwater, and its flow can be represented by chloroalkaline indices CAI I and CAI II [28]. Positive value of chloroalkaline index revealed direct ion exchange between Na + and K + from water and Ca 2+ and Mg 2+ with the rocks. When the value of CAI is negative, ion exchange between Mg 2+ and Ca 2+ from water and Na + and K + with rocks happens. e resultant value of CAI I was lying in between −7.7824 and 6.8758 and CAI II −0.0790 and 6.8213 (Table 4). ese values indicated that 70% studied  area belonged to negative category and 30% felt in the positive zone. us, the findings clearly indicated that exchangeable cations can also be used to indicate the chemical composition of groundwater of the study area. Gibbs (1970) proposed a diagram for interpretation of the mechanism of major ion chemistry of groundwater samples [57]. e Gibbs diagram explains the three different fields, namely, precipitation dominance, evaporation dominance, and rock dominance. Gibbs ratio was calculated with the help of the following formula:
e concentration of all ions was taken in meq L −1 . Gibbs diagram was plotted in between Gibbs ratio (cation or anion) and total dissolved solid. In the present study area, the value of Gibbs ratio 1 ranged from 0.01 to 0.66 with an average value of 0.33. e value of Gibbs ratio 2 was in between 0.04 and 0.45 with an average value of 0.143 (Table 4). From Figure 12, it can be interpreted that most of the samples belonged to the rock dominance area, representing the influence of the rocks on groundwater aquifer.

Conclusions
e groundwater of Udham Singh Nagar district was alkaline and hard to very hard in nature. e values plotted on the USSL diagram suggested that the groundwater samples belonged to C2S1 and C3S1 categories, indicating medium to high salinity and low sodium hazard. e Wilcox diagram suggested that most of the groundwater samples fall in excellent to good category, and some water samples belonged to good category. On the basis of SAR, RSC, SSP, and PI, all the groundwater samples were observed to be suitable for irrigation purpose. Based on the MH values, 54% groundwater samples were found to be unsuitable for irrigation purpose. e most dominated cation was Ca 2+ followed by Mg 2+ , Na + , and K + , while the order of domination of anions was HCO 3 − > Cl − > SO 4 2− > NO 3 -> CO 3 2− . Predominance of cations such as magnesium and calcium in the groundwater indicated pollution to anthropogenic activities. All the groundwater samples showed simple mixing of ions as no ion is predominant.
Data Availability e data (raw process) used to support the finding of this study are included within the research article.

Conflicts of Interest
e authors declare that they have no conflicts of interest.