Public environmental expenditures and rural water quality: evidence from Kazakhstan

Abstract

This study is aimed to evaluate how public environmental expenditure relates to water quality in rural regions of Kazakhstan. It was held in Akmola and Zhambyl to compare regional disparities. The investigation process integrated regional investment data and hydrochemical indicators, such as total dissolved solids (TDS) and major ion composition. The novelty of this study lies in integrating long-term regional environmental expenditure data with hydrochemical indicators of rural drinking water quality to evaluate investment effectiveness under contrasting climatic and hydrogeological conditions in Kazakhstan. Methodology included statistical analysis, comparative regional assessment, and hydrochemical analysis of water. The geological conditions of the region were also taken into account when considering water quality outcomes. During the investigation, it was found that higher investments do not necessarily lead to improved water quality. The Zhambyl region showed relatively stable and optimal water quality despite the lower investment rates. Conversely, the Akmola region, despite attracting large amounts of investments, exhibited lower water quality. These regional disparities appear to be associated with differences in climatic and hydrogeological conditions rather than investment levels alone. In addition, areas with waterlogged soils showed elevated concentrations of TDS, indicating the significant influence of hydrogeological factors. Linear trend analysis demonstrated significant increases in environmental expenditure per capita in both regions (Akmola: slope = 3,439.95 tenge/person/year, R² = 0.626, p = 0.0064; Zhambyl: slope = 1,944.97 tenge/person/year, R² = 0.700, p = 0.0026), with both trends independently confirmed by the Mann–Kendall test (p < 0.01). Hydrochemical analysis revealed substantially higher and more variable TDS concentrations in Akmola, including values exceeding 5,000 mg/L in some localities, whereas most values in Zhambyl ranged between approximately 200 and 400 mg/L. These findings indicate that higher environmental expenditure does not necessarily correspond to better rural water-quality outcomes because regional hydrogeological and climatic conditions may substantially influence the observed relationship. These findings support region-specific environmental investment policies that account for local hydrogeological, climatic, infrastructural, and institutional conditions when allocating public resources for rural water-quality improvement.