Integrative Evaluation of Urban Groundwater Wells Using Physicochemical Parameters, Water Quality Indices, and Trace Metal Indicators (Cr, As): Sarbisheh Plain, South Khorasan, Iran

Groundwater quality is influenced by the region’s natural climatic–geological setting and anthropogenic practices such as agriculture, industry, and mining. Ongoing evaluation of groundwater quality is therefore vital for secure drinking supplies, agricultural production, industrial operations, public-health protection, and efficient treatment processes. This study aims to evaluate the quality of groundwater in Sarbisheh Plain, South Khorasan, Iran. Water-quality data for 2020 and 2021 were examined and analyzed for the 18 wells supplying Sarbisheh’s water demand. The status and concentrations of 12 physico-chemical parameters during the mentioned years were evaluated and statistically analyzed using SPSS software. The overall quality of the studied water resources was also evaluated using groundwater quality index. The results showed that the average EC in the water-supply wells of Sarbisheh is approximately 4513.5 μS/cm, which exceeds the standard limit. The TDS values also ranged from 596 to 8511 mg/l, with the mean for most wells falling outside the acceptable standard range. Among the studied ions, sodium and chloride exhibited the highest concentrations at 682.1 mg/l and 677.3 mg/l, respectively, while potassium and fluoride showed the lowest levels at 28 mg/l and 0.3 mg/l. Calculations of the water quality index for the 18 wells showed that 33.33% of the wells fell into the good category, while the remaining wells ranged from poor to very poor. The results demonstrated that assessment and monitoring of groundwater quality in study area are very important; moreover, for drinking purposes, treatment is required to improve water quality and meet the necessary standards.