ABSTRACT
"Purified water" is described as having organoleptic, physical, chemical and microbiological characteristics that does not represent any risk for human health. The present study was based in the determination of water quality from 21 ozone and sedimentation water filters form the Faculties of Agronomy, Architecture, Chemical Sciences and Pharmacy, Economic Sciences, Enginery and Odontology; The School of History, Social Work; The University Gym and The Center of Sea Studies (CEMA) (Spanish acronyms); located in the central campus of Universidad de San Carlos de Guatemala. The main purpose of the study to determine if the water samples extracted from the filters a qualified for human intake. This evaluation is based on the quantity of total and fecal coliforms according to the most probable number method (MPN) and the presence of Escherichia coli (E. coli), both evaluated under [COGUANOR NTG 29001],2010 standards. The results indicate that the filters located in the Faculties of Chemical Sciences and Pharmacy, Economical Sciences, Social Work, Dentistry are over the safety limits for total coliforms established for potable water under COGUANOR standards. Also the samples taken in the Faculties of Economical Sciences and Chemical Sciences and Pharmacy show a positive result in the presence of E. coli too, means that the water extracted from those filters is not qualified for human intake. Keywords: purified water, ozone filters, sedimentation