Characteristic of groundwater well quality using bivariate analysis: A case study at USM Engineering Campus, Penang

Abstract

This study was carried out to determine the water quality at USM tube well based on the physico-chemical and biological characteristics. In this paper, the groundwater sample was extracted from the USM tube well through pumping process. The sample was collected twice a month for one year (n=24). Water quality analysis was conducted by in-situ and laboratory testing. Ten (10) water quality parameters such as turbidity, colour, total dissolve solid (TDS), conductivity, pH, total hardness, heavy metal (Fe & Mn), total coliform and E-Coli were analysed and compared the result with Raw and Drinking Water Quality Requirement established by Malaysian Standard (MS2320). The relationship between parameters was also analysed statistically using Spearman’s correlation coefficient (r2). Result shows that Fe has a strong positive correlation with Mn and conductivity. The correlation between conductivity- Fe and conductivity- Mn have a strong positive correlation with r2 between 0.6 and 0.79. This indicates that cation minerals in soil, sediment and rock such as Fe and Mn leach out into groundwater and thus contribute to the electrical conductivity of groundwater. Moreover, Mn demonstrated a significant positive correlation with conductivity and TDS. The strong relationship between Mn- TDS (r2 = 0.77) and Mn- conductivity (r2 = 0.75) respectively, suggested that the concentration of Mn in USM tube well was influenced by dissolution minerals in groundwater. On the contrary, the correlation between turbidity-hardness, turbidity-E-coli and turbidity-total coliform showed a very weak positive (r2 < 0.2) and negative (r2 < - 0.2) significance, which indicates that turbidity was not significant with all parameters present in USM tube well. Overall, it can be concluded that the water quality from USM tube well is not recommended for drinking, which did not comply the Malaysian standard of drinking water. However, it can be used for other purposes such as irrigation and industrial activities.