This study was undertaken to evaluate the drinking water quality based on physicochemical properties and chemical compositions of the supply water in the Daedeok Campus, and to verify the analytical reliabilities of ICP-MS and IC equipped in the Central Research Facilities at Chungnam National University , Korea. The supply water belongs to $Ca^{2+}-({HCO_3}^-+{SO_4}^{2-})$type, whereas the original water from the Daecheong lake belongs to $(Ca^{2+}-(Mg^{2+})-{HCO_3}^-$ type. Generally, temperature (14.1$^{circ}C$), pH (6.95), Eh (0 mV), electrical conductivity (117${mu}$S/cm) and TDS (86.975mg/l) of supply water were higher than those of original lake water . Results using WATEQ4F revealed that potentially toxic ions of the supply water might exist mainly as free metals ($M^{2+}$) and a small amount as ${CO_3}^{2-}$ and $OH^-$ complexes. Also, the water composition belongs to the kaolinite field. Calculated average enrichment indies of the supply water normalized to lake water for anions, mamor cations, toxic cations and total ions are 1.05 , 1.56, 13.05 and 1.17 , respectively. Those values of the ground water in the Daedeok Campus showed 1.71, 4.78, 5.71 and 2.49 , respectively. However , contents of all constituents of these water are within the drinking water standard. All samples were filtered before the chemical analysis. Pale yellow or yellowish brown colored materials of colloidal particles coated the filter paper to thickness of 0.02 to 0.2mm. these are mainly Fe-Cy-Zn compounds with traces of Ni and Pb, the net weights of which compounds range from 0.01to 3.20mg/l. Most elements did not show any conceivable filtering effect of Cu, Fe and Zn. Especially, mean concentration of total Fe decreased considerably from 168.52${mu}g$/lto 42.58${mu}g$/l by filtering .