Hydrogeology and groundwater geochemistry of the Tampin district, Negeri Sembilan, Malaysia

Abstract

Groundwater assessment for domestic use is vitally important to prevent health issues to users who are depending on groundwater as their main supplies especially during water crisis and drought. Often, quality of groundwater is assessed only on their safety for use, the source of natural pollutants especially from geological materials is often not reported. Therefore, the main aim of this study was to determine the water quality of tubewells and also to identify potential pollutants and their sources using Piper and Gibbs methods as an addition for water quality assessment. The Piper diagram is used to provide an understanding on the geochemical evolution of the groundwater and the Gibbs diagram shows the relationship of the water composition and the aquifer. The analysis was conducted on 38 tubewells in the District of Tampin. This district has experience water crisis in 2015 when the water in the Gemencheh Dam dropped to a critical level due to the El Nino phenomenon. For the analysis purpose, geochemical data from 2013 to 2015 from 8 active tubewells were used. Based on the Piper Diagram, the dominant element found in wells are Ca2+HO3-, followed by Na+ HO3- and Ca-Na- HO3-. The hydro-chemical evolution is mainly due to the interaction between rocks and precipitation of groundwater based on the Gibbs Diagram. On the water quality, the level of Fe is found to be increasing in 3 wells (NTPPW 18, RTG 27 & RTG 53) over the years, while other critical elements remain to be in acceptable level. The overall finding shows that pollutants may enter the wells from weathered rock and also from rainfall that will saturate as well as draining heavy metal ions into wells around the Tampin District.