In this laboratory study, As and Cr remediation process by Fenton's and FeSO4/K2Cr2O7 reagent was applied on different water samples. Optimization studies were performed on zero-valent iron column. Maximum removal efficiency is obtained by using a 150 g zero-valent iron column with 40 mg, FeSO4/20 mu l H2O2 and 40 mg FeSO4/20 mg K2Cr2O7 for 100-ml samples. The effect of water hardness on the removal efficiency of As and Cr was investigated in contaminated water. It was observed that water hardness increases the removal efficiency of As and Cr. The method was applied to spiked tap water and Ankara stream water. The As and Cr remediation efficiencies in the stream water were 90.2%, 89.9% and 95%, 93.4, respectively, for both methods. The As and Cr remediation efficiencies in the tap water were above 98% for both methods. As and Cr were determined by ICP-OES and the method's accuracy was realized with Certified Reference Material (NIST 1643e).