Contamination by Pathogenic Microorganisms in Water used for Agricultural Irrigation on the Sabana de Bogota, Colombia

Abstract

The aim of this study was to evaluate the microbiological quality of water used to irrigate food crops, which can lead to the spread of certain microorganism, such as Escherichia coli, which poses a high risk of contamination for food, especially food consumed as fresh vegetables and milk, making it important to monitor the hygienic state of water based on the detection of 'indicator' bacteria, which are normally only present in human and animal intestines, such as coliforms, which have been accepted worldwide as a unfailing parameter. To evaluate the water quality, the coliforms present in the water used for agricultural irrigation on the Sabana de Bogota were quantified in the La Ramada irrigation district. Water samples were taken at ten agricultural irrigation points in municipalities around Bogota. The methodology for the analysis included the technique that uses serial dilutions of samples in a specific culture media. In the different sampled sites where the water quality used for irrigation was evaluated, the total and fecal coliforms values were higher in CFU than the established limits (Decree 1594 of 1984) and values were found in some samples that were higher than $1×10^6 \>CFU \>100/mL$ for total coliforms and $1×10^5 \>CFU \>100/mL$ for fecal coliforms. This study indicated that, with the current conditions of some water sources on the Sabana de Bogotá, there is an inherent source of contamination, creating an obstacle for agricultural irrigation and a microbiological risk for consumers.