This work compare the efficiency of water treatment from Rimac river. Samples from different phases of water treatment (decanted, filtered and chlorinated) were compared with not treated samples. Coliphages quantification was made by Simple Layer and Membrane Filter methods. Most Probable Number (NMP) and Membrane Filter methods were used to assessment of Total Coliforms, Coliforms Thermotolerants and Heterotrophic Bacteria. The standard strain of E. coli C ATCC 13706 was used as coliphages host. The averages of quantified coliphages were of 2267,25 UFP/100 mL in samples with out treatment; 2,11, 2,04 and 1,07 UFP/100 mL in the water samples from decanted, filtered and chlorinated treatment respectively. Total Coliforms and Coliforms Thermotolerants were not detected in samples of chlorinated water. The correlation between coliphages and Total Coliforms in samples of decanted and filtered water (r = 0,3793 and r = 0,3629 respectively) were significant (p <0,05) Samples with out treatment don't were significant (r = 0,3048, p>0,05). Correlations between coliphages and the Coliforms Thermotolerants were significant with water samples from treatment decanted, filtered and chlorinated (r = 0,7129; 0,5326 and 0,4612, p <0,05). The microbial removal percentages were 99,95 % for the coliphages, 99,99 % for the BH and >99,99 % for the CT and CTT.