Long-Term Durability of HDPE Geomembranes in Mining: A Non-Parametric Statistical Approach

The long-term reliability of geomembranes is essential for maintaining environmental safety and protecting human health, particularly when applied in demanding environments such as mining. This study evaluates the long-term performance of a 2 mm high-density polyethylene (HDPE) geomembrane after 12 years at a gold mining tailings pond in Brazil. As built performance data were unavailable, so analyses were based on GRI GM13 standard. Three samples from various dam locations were analysed using the Kernel Density Estimator (KDE) for non-parametric statistical analysis. The geomembrane’s failure probability in terms of tensile strength was 19%, indicating an 81% success rate as a hydraulic barrier. The lowest stress crack resistance (SCR) among samples exceeded the 50% SCR of the GRI GM13 standard. Significant antioxidant depletion was noted in the Standard Oxidative Induction Time (Std-OIT) tests, down to 14% of the minimum GRI GM13 value, while the High-Pressure Oxidative Induction Time (HP-OIT) showed only slight depletion, down to 80% of the minimum GRI GM13 value. Environmental analysis revealed no significant contamination, confirming the geomembrane’s effectiveness.