ANALYSIS OF MICROBIOLOGICAL CONTAMINATION IN AQUIFERS, IN THE URBAN REGION OF OBLIGADO AND HOHENAU ? PARAGUAY

In Paraguay, 85% of homes have water supply from enhanced sources, 63% are delivered by a distribution system. Likewise, 79% of homes have sanitary drains and 11% are connected to an effluent treatment system (Secretar?a T?cnica de Planificaci?n del Desarrollo Econ?mico y Social, 2015), this condition hints to superficial pollution problems as well as underground water. The Capiibary Stream watershed, situated in the Department of Itap?a, Paraguay and established on the Guarani Aquifer System (SAG, in Spanish), aquifers exploited by deep wells where the presence of fecal coliform is found in 60% of sampled wells (Protecci?n y Manejo de Aguas Subterr?neas en Paraguay PAS-PY, 2012). The study calculated variations in total coliforms in groundwater watershed detected in the center of Obligado and Hohenau, the analysis of groundwater property was based on data from 59 water samples taken over a 10-year period (2006-2016) in 17 deep wells, variations of total coliforms were estimated. For the statistical processing, the analysis of variance and contrast of means (Duncan test) with margin of error 5% were performed. It was determined the variations of the overall coliforms in the study period 2006 to 2016, the presence of total coliforms topped the maximum acceptable threshold. Similarly, deep wells were detected in Obligado, whose standards extended up to 998 CFU / 100ml. Lastly, the results were contrasted with World Health Organization (WHO, 2006) parameters and the Official Paraguayan Standards ERSSAN (ERSSAN, 2017) Law N?. 1614/2000.