Ecological Assessment of the State of Groundwater in the Upper Keles Field in Kazakhstan

This study focuses on the sanitary reliability of artesian wells and the protection of groundwater resources in the Upper Keles field, which provides drinking water to the Kazygurt settlement in southeastern Kazakhstan. In 2024, we collected 160 water samples from 10 wells with depths ranging from 15 to 60 m and analyzed them seasonally for physicochemical, chemical, and microbiological indicators. The parameters included pH, electrical conductivity, nitrate levels, heavy metal levels, and Escherichia coli. The analysis revealed significant differences in electrical conductivity (P = 0.01) and redox potential (P = 0.02) between well groups. Seasonal changes were also observed in nitrate concentrations (P = 0.02), which showed a positive correlation with pH (r = 0.65, P < 0.01) and a negative correlation with water temperature (ρ = –0.48, P < 0.05). Multiple regression indicated that both aquifer type (β = 0.35, P < 0.01) and agricultural activity in the surrounding area (β = 0.42, P < 0.01) play an essential role in nitrate accumulation. These results highlight the vulnerability of local groundwater to anthropogenic impacts and underline the importance of continuous monitoring and stricter regulation of agricultural practices. At the same time, the study has limitations: the data set is geographically restricted and covers mainly primary pollutants, while the role of emerging contaminants remains a topic of further research.