T The location of the research area is administratively located in Cilodong andsurrounding areas, Cilodong District, Depok City, West Java Province atcoordinates 6o26\'13.13\" LS and 106o50\'07.93\" BT. . The research area is an areathat is densely populated enough to affect the supply of clean water, so researchwas conducted to determine the Quality of Groundwater. The study wasconducted by measuring MAT and taking groundwater samples carried out in 18dug wells and 1 borehole with 12 groundwater samples carried out laboratorytests producing anion and cation elements. From the laboratory results,calculations were carried out using the Ogata Method (1970) to determine thedistribution of elements. The study site had a groundwater level distributionranging from 72.05 to 110.31 (dml). Chemical facies in the research area can begrouped into 2 (two) facies, namely: Facies Na (sodium) + K (Potassium), Ca(calcium) + Mg (magnesium) and Facies Cl (chloride) + SO4 (sulfate), HCO3(bicarbonate). Using the Ogata method (1970) can be known the initialconcentration and final concentration of the elements calcium (Ca) andmagnesium (Mg). At SG-10 with a distance of X (50m) has a final concentrationof 7.1989 mg / L / in Ca elements and 3.5499 mg / L in Mg elements at a period of365 days. At SG-18 with a distance of X (70m) has a final concentration of10.135999 mg / L in Ca elements and 4.53599 mg / L in a period of 365 days. Forgroundwater quality according to Permenkes No.493 resistant 2010 there areseveral parameters that are not suitable such as fluoride, nitrate and pH