Groundwater wears the crown of being one of the significant drinking and domestic water sources worldwide, but the increasing industrialization and urbanization have overexploited this valuable resource, creating an extreme increase in demand for it (Bear, 1979; Foster, 1998; Gautam et al., 2017; Gyeltshen et al., 2019; Taloor et al, 2020; Adimalla et al., 2020, Adimalla and Taloor 2020 ). Likewise, in Udham Singh Nagar, Uttarakhand groundwater holds an essential role in domestic, agriculture and industrial uses, making it quite an important task to keep a strict check on its water quality (Milovanoic, 2007; Magesh and Chandrasekar, 2011; Nair et al., 2021). But in recent economies, the rapid rate of industrial, agricultural and domestic activities has contaminated the water quality with hazardous waste discharge, thus influencing poorly on drinking water (Haque et al., 2020; Sarkar et al., 2020; Karunakalage et al., 2021). The increase in water contamination not only takes a toll on water quality but also affects human health. Both quality and quantity of groundwater are equally significant for accomplishing several purposes (Sarath Prasanth et al., 2012; Wadie and Abduljalil, 2010; Gaur et al., 2013). As groundwater quality data gives compelling clues to the geological history, a slight trigger in water quality can determine an area's physical and chemical parameters (Walton, 1970; Subramani et al., 2005; Schiavo et al., 2006; Krishna Kumar et al., 2011; Jasrotia et al., 2019).
The water quality can be determined mainly by the geochemical processes, chemical and mineral composition of the aquifer rocks, residence period, and additional factors related to groundwater flow and effluents addition through human interference (Faniran et al., 2004; Lopez-Maldonado et al., 2017). Over the time, accelerated and unchecked population growth, urban and industrial growth have affected environmental condition of the surface and subsurface in different areas. Since groundwater is highly potential in accomplishing the water demand in future so it is imperative to avoid harmful activities of human which affect the groundwater system connected hydraulically thus reducing the accessibility of these alternate potable sources of water (Adekunle et al., 2007; Kumar and Divya, 2012). Once the groundwater gets contaminated, it is impossible in restoring its quality even by eliminating the pollutants from the source (Kumar and Ahmed, 2003; Jain et al., 2010). Various location and environments determine the quality of a water resource. For instance, the saline-alkali soils are affected by water quality used for irrigation. The suitability of irrigation water can be determined by saline and sodium hazard indicators (Nishanthiny et al., 2010). Assessment and sustainability check of groundwater is crucial in areas of critical economic and social significance like arid and semi-arid areas (Guo et al., 2019; Singh et al., 2020). Thus, groundwater quality is an effective parameter which pass on fundamental information to concerned citizens and policymakers (Sujatha and Reddy, 2003; Fagbote et al., 2014).
The groundwater chemistry also provides the information of atmosphere, soil, weathering, pollutants, saline intrusion, land clearance, domestic wastes along with lithology and dwelling time of water contact with rock layers (Pawar and Shaikh, 1995; Atulegwu and Njoku, 2004; Babiker et al., 2007). The seven major chemical parameters present in groundwater are Ca2+, Mg2+, Cl−, HCO3−, Na+, K+ and SO42− which efficiently classifies and assesses groundwater quality (Jamshidzadeh and Mirbagheri, 2011). Monitoring the groundwater sources gives an idea about the water characteristics, the variability in water quality, emerging water problems, presence or invasion of hazardous waste and solution for treating the prevailing water pollution (Suk and Lee, 1999; Kumar et al., 2010; Kaown et al., 2012). Therefore, evaluation of quality in groundwater, establishing a database and also the development planning of water resources located in the Tarai region of Kumaun are fruitful steps taken towards the society. In respect to this perspective, Udham Singh Nagar district is selected for its groundwater quality assessment as groundwater is the primary source for water supply here and also Uttarakhand’s biggest industrial hub; State Industrial Development Corporation of Uttarakhand Limited (SIDCUL). The industries under SIDCUL produces poisonous effluents, of which a significant portion gets discharged as untreated waste (Seth et al., 2014; CGWB, 2011). Such kind of effluents that are treated partially becomes the main source for surface, groundwater and subsurface contamination, thus posing a harmful warning for groundwater resources where pollution is not noticeable with immediate effect. Since Udham Singh Nagar is also dominated by agriculture and domestic activities the harmful discharge and untreated wastes pollutes the groundwater thus taking a huge toll on health of the local population (Banerjee et al., 2009; Sharma et al., 2012; Panwar and Srivastava, 2012).
In this study, total 18 physico-chemical water quality parameters of pre-monsoon season (2016) have had been assessed in respect to Bureau of Indian Standard (BIS, 2005). This paper aims in characterizing the quality of groundwater which is dwelling within the shallow aquifers by determining its hydrogeochemical facies. This will assist in implementing reasonable knowledge on possible changes in groundwater with respect to the rapid development in industrial belt of Udham Singh Nagar. Therefore, it is very crucial to have adequate knowledge on the quality of natural baseline, so that any alarming changes in the environment can be measured with felicitous confidence (Edmunds et al., 2003).