Drinking Water Field Analyses for the Detection and Enumeration of Coliform Bacteria in Rural Guatemalan Highlands

An analysis of drinking water contaminant concentrations in the highlands of rural Guatemala evaluated the Coliscan EasyGel as a field method for the detection and enumeration of coliform bacteria in drinking water and found it adequate. In developing countries like Guatemala, many deaths among infants and young children may be due to dehydration, malnutrition, or other complications of waterborne bacterial infections. Students and engineers are challenged to find sustainable means to provide safe drinking water. A field applicable method of quantifying microbiological contamination is needed to improve the evaluation of engineering solutions. A pour plate method using the patented Coliscan EasyGel medium is commercially available and marketed for field use by Micrology Labs Incorporated. However, the validity of the field data is called into question when the results are compared qualitatively and quantitatively to duplicate Membrane Filtration (MF) analysis using M-Endo medium, an ASTM accredited method. To evaluate comparability, this work splits subsets of the samples for duplicate MF analysis and non-parametric statistical evaluation due to the non-normal nature of data distribution.