A standardized parametric weighting system for water quality indexing: advancing water resource management through...

Weighted water quality indexing is constrained by subjective expert judgment, statistical tools, and complex models that undermine environmental monitoring and management. This study advances environmental assessment through a standardized parametric weighting system that improves decision support by prioritizing contaminants via sample-specific assignments based on established permissible limits. The approach quantifies contaminant exceedance intensity, incorporating ratio and deviation calculations, censored data handling, and piecewise logarithmic scaling for parameters with low permissible limits (e.g., potentially toxic elements [PTEs]). Validated on datasets from southern Nigeria and eastern Ghana, the system increased sensitivity coefficients across both datasets, enabling more responsive contaminant prioritization. Effectiveness was demonstrated for prioritizing PTEs (such as Pb and Fe) alongside conventional parameters (including pH, Mg²⁺, Ca²⁺, SO₄^2-, HCO₃^-). In Nigeria, Water Quality Index (WQI) eclipsing errors were reduced, improving hazard detection accuracy. In Ghana, parameter prioritization within the Pollution Index of Groundwater (PIG) was refined. The method provides an accessible, reproducible tool for water quality weight assignment and intensity-based pollutant ranking, supporting environmental toxicology and hazard assessment. Its operational simplicity suits diverse monitoring regimes, offering managers a practical approach for equitable, targeted water quality assessment. This work advocates for more reliable water quality assessment to enhance attainment of multi-sustainability goals.