The springs of the Republic of Azerbaijan and the evaluation of their hydrogeological and ecological security

Abstract This study explores selected hydrogeological characteristics of springs in Azerbaijan, focusing on their distribution, discharge, dissolved solid water quality, and potential for sustainable use. The study is primarily based on the results of spring monitoring programs conducted by the Geological Exploration Agency under the Ministry of Ecology and Natural Resources, as well as the Azerbaijan State Water Resources Agency from 2020 to 2023. Springs in 61 of the country’s 67 administrative districts were investigated using the requirements of “Drinking Water. Hygienic Requirements and Quality Control” AZS 929:2023 state standard in the Republic of Azerbaijan. A total of 1985 springs were evaluated. Many springs exhibited low to medium flow rates below 1 l/s, and mineralization that does not exceed drinking water standards. The mean discharge rate for 1928 springs was 2.08 l/s, with a large range of 0.0002–400 l/s, with an overall median value of 0.43 l/s, a large standard deviation of 12.76 l/s, and an extremely high positive skew of 21.03, reflecting a preponderance of low-flow springs. Total dissolved solids measured in 1480 springs had a mean value of 0.55 g/l, a range of 0.30–20.70 g/l, with a median value of 0.40 g/l. The standard deviation was 0.79 g/l, and the data set again showed a high positive skew of 14.55, indicating that the majority of springs analyzed had somewhat lower mineralization within acceptable drinking water limits. Hydrogeological investigations confirm that most springs investigated comply with national water quality standards, although areas with higher mineralization require careful monitoring.