Study of Groundwater Quality from Monitoring Well of Landfill in Songkhla Municipality

Abstract

This research studies the groundwater quality from monitoring wells at the landfill of Songkhla Municipality. Groundwater samples were collected monthly over a six-month period from four monitoring wells located at the northern, southern, eastern, and western of the landfill. During a site survey, it was found that monitoring well 3, located to the western of the landfill, was damaged, making groundwater sampling from this well impossible. The analysis of groundwater quality from the remaining three monitoring wells showed that the water appeared brown, contained sediment, and had a slight odor. The pH values of the groundwater from all monitoring wells met the groundwater standard criteria. However, heavy metal analysis showed that groundwater from Monitoring Well 1 (East) contained arsenic, cadmium, and lead concentrations exceeding the standard limits. Monitoring Well 2 (South) showed arsenic, manganese, and lead concentrations above permissible thresholds. Furthermore, Monitoring Well 4 (North) showed arsenic and lead concentration exceeding the standard. These studies indicate that arsenic and lead concentrations in groundwater from all monitored wells exceeded the standard groundwater quality limits. The impact on residents living around the landfill site is minimal, as most rely on tap water for domestic consumption.