Unveiling water quality patterns in the non-industrial mountainous region of northern Pakistan: A hydrological perspective

• Comprehensive quality analysis of spring water was carried out. • Water was categorized as drinkable and non-drinkable based on WQI values. • Heavy metals pose serious health risks, exceeding maximum allowable limits. • Results indicate sustainable water treatment solutions. Springs are a major supply of drinking water for many rural communities, but both geogenic and human activities are posing an increasing threat to their quality. Despite their significance, spring systems in study area are not well researched and no prior study has provided a thorough examination combining physicochemical profiling, heavy metal estimation and microbiological examination. In this study, thirty-six spring water samples from various regions across Azad Jammu and Kashmir (AJK) were examined to determine their potability and chemical composition. Physicochemical analysis, heavy metal quantification, and microbiological evaluation followed by Statistical analyses, such as Principal Component Analysis (PCA) and Pearson correlation, were performed to recognize key patterns and source contamination. Over 80% of the samples were classified as "unsuitable for drinking," based on WHO standards, according to the Water Quality Index values ranging from 397.6 to 2008.2. In most of the samples elevated toxic heavy metal levels, including nickel (0.09-0.25 mg/L), lead (0.49-2.21 mg/L), and cadmium (0.03-0.06 mg/L), were observed. Microbiological contamination was also common; in most springs, levels of E. coli , fecal coliforms, and total coliforms were found to be within dangerous ranges. With considerable loadings from bacteria, chemical oxygen demand, and nutritional factors, Principal Component Analysis (PCA) revealed two main components that account for more than 60% of the variance. The hydro chemical facies obtained from the Piper diagram showed that Ca–Mg–SO 4 type water predominated. This study provides first-region specific baseline data set employing an integrated analytical approach, offering new insights into the spring profile of the area. Results obtained highlight urgent need to conduct routine monitoring, raise community awareness, and implement legislative changes to protect spring water sources. The findings of the study offer vital comprehension for water resource planners, environmental managers, and local health authorities looking to enhance water quality and protect public health in the area.