Synoptic sampling to identify the major anions and cations of coal ash transport river by the application of isometric log-ratio transformation.

Water quality in coalfield-adjacent river systems is significantly impacted by mining activities, yet accurately quantifying pollution sources remains challenging. Present study focuses on differentiating the water-chemistry of parent-stream and its source areas surrounding coalfields where pollution is extensive and complexly affected by ground and surface water interactions. Through this study, an effort has been made to show the application synoptic sampling technique integrated with Principal Component Analysis (PCA) and the synoptic mass balance method to quantify the level of pollution in Nalkari River, India. This study provides a comprehensive analysis of the impact of mining operations on stream water quality through laboratory techniques and statistical methods. In this study, stream load is quantified by the synoptic mass balance method, in which the spatial distribution of the stream is studied using detailed sampling. In addition, the PCA was conducted both with and without the application of the Isometric Log-Ratio (ILR) transformation, as implemented in the laboratory analysis of the collected samples. The PCA analysis shows positive loadings of Cl^-, Na⁺, K⁺, Ca²⁺, Mg²⁺, SO₄^-, Fe⁺ and HCO₃^- as factor 1 in the Nalkari River stream. The study identifies PCA with ILR transformation, dominant cations (Na + > K + > Ca²⁺ > Mg²⁺ > Fe⁺) and traced anions (Cl^- > HCO₃^- > SO₄^- > F^- > NO₃^-) in surface water samples, providing deeper insights into underlying biogeochemical processes. The mining activity affects the watershed by mobilising contaminants, which depicts the water chemistry under the study and by integrating the synoptic sampling and PCA, which resembles a conceptual contaminant dynamic model that can be used to develop the remediation framework.