Landfill leachate a new threat to water quality: a case study from the Temperate Himalayas.

Landfills are commonly seen as the most cost-efficient and practical approach to waste management in various regions around the world. Nonetheless, the infiltration of hazardous materials from poorly managed dumping sites remains a significant environmental issue in most developing countries such as India. Leachate serves as a prominent point source of contamination in many environmental media like soil, groundwater, and surface water around the world. So the prime issues humans are experiencing are associated with water quality. Thus, the investigation was undertaken to assess the impact of leachate from the Achan landfill on surface water quality in the Temperate Himalayas. Monitoring was done during in all four seasons, viz., spring, summer, autumn, and winter. Among the sites, the leachate outflow site was found to have the highest mean value of pH (7.95), EC (2.16 dS/m), total nitrogen (2.64 mg/l), P (4.75 mg/l), K (1.41 mg/l), Ca (107.45 mg/l), Mg (54.93 mg/l), Zn (0.8 mg/l), Fe (1.78 mg/l), Cu (0.66 mg/l), Mn (0.81 mg/l), BOD (21.47 mg/l), COD (66.24 mg/l), temperature (14.22 °C), turbidity (14.29 NTU), while lowest mean values of all parameters were recorded at control site. Among the seasons, summer season was found to have maximum value of pH (7.9), EC (2.36 dS/m), total nitrogen (2.54 mg/l), P (4.0 mg/l), K (0.89 mg/l), Ca (85.94 mg/l), Mg (43.91 mg/l), Fe (1.4 mg/l), Cu (0.52 mg/l), Mn (0.64 mg/l), BOD (22.82 mg/l), COD (65.87 mg/l), temperature (18.99 °C), and turbidity (8.49 NTU). The maximum mean value of Zn (0.66 mg/l) was recorded during winter season, while other parameters were found to be minimum during winter season. From this study, we concluded that a decreasing trend was observed during all the seasons in the concentration of all physico-chemical parameters with an increase in distance from the landfill. So it is recommended that the leachate should be treated at the source before disposing into the water body and the landfill should be lined properly to prevent the entry of leachate into water sources.