G roundwater is a source of clean water that is often used. In groundwater, iron and manganese are often found in both dissolved and sedimentary forms. In order to fulfill the need for clean water that meets the requirements in terms of quantity and quality in accordance with the quality standards for class B according to the PerMen-Kes No.416 th.1990 which includes physical, chemical, biological and radioactive requirements, a water treatment process is required.One of the water treatment processes that can be used is filtration using activated carbon as an adsorption medium. The processing with activated carbon is not only easy in operation but also can absorb pollutants in water such as taste, smell, color, organic and inorganic materials.The filter column used in this study is a tube made of acrilic material with a diameter of 0.095 m and a media thickness of 0.8 m. Columns are operated continuously through activated carbon media. This study varied the filtration rates 4, 6 and 8 m / hour and the media thickness was 0.4; 0.6 and 0.8m.The results showed that the optimum conditions were a filtration rate of 4 m / hour and a media thickness of 0.8 m. Under these conditions the raw water that can be treated is 5,208 m2 with effluent iron concentration of 0.940 mg / i and 0.924 m3 with effluent manganese concentration of 0.497 mg / l. The effluent generated from the operation when collected before distribution will produce a mixed concentration. The concentration of this mixture can extend the operating time of the column because the resulting concentration value is smaller than the effluent concentration value if it is directly distributed. The volume of treated water obtained and the results of the calculation of the concentration of the mixture is 11.676 m3 with an effluent iron concentration of 0.999 mg / l and 1.428 m3 with a manganese effluent concentration of 0.496 mg / l.