Hydrogeochemical controls on drinking and irrigation water suitability of spring water in the Champawat District, Uttarakhand: insights from multivariate statistical analysis

In the Himalayan region of Uttarakhand, natural springs constitute the primary freshwater source for a large rural population. To investigate the spring water quality of the Lohawati catchment, 27 spring water samples (n = 27) were collected and analyzed to identify the contributions of geogenic and anthropogenic inputs to drinking and irrigation water quality. Major ions were found within the permissible limits, but fluoride exceeded 1 mg L−1, indicating potential fluorosis risk. The dominant hydrochemical facies are Ca2+–Mg2+–Cl−–SO42− and mixed types, with evapotranspiration and rock–water interaction as the primary processes controlling chemistry. Among heavy metals, Fe exceeded the acceptable limit (0.3 mg L−1), while Cu surpassed the permissible limit (0.05 mg L−1) in 66.7% of samples. Due to this metal load, the water quality index indicates that all samples fall into the ‘unsuitable for drinking’ category, yet they remain suitable for irrigation purposes. Correlation matrix and hierarchical cluster analyses suggest that elevated NO3- and SO42- concentrations are primarily associated with anthropogenic activities, particularly the use of fertilizers. Principal component analysis revealed that spring water quality is governed by the combined influence of geogenic and anthropogenic factors.