Bacterial testing plate incubation in developing regions

Prefabricated bacterial testing plates are frequently used during assessment, implementation, and monitoring phases of Engineers Without Borders (EWB) water projects. Results from these plates are used to determine the presence of biological contamination in surface and ground water sources. However, lack of incubation equipment in developing regions of the world—to provide standard temperature and environmental conditions for bacterial growth—is a significant challenge to utilizing such plates for EWB projects. Using a common water source, several variants of prefabricated bacterial testing plates were inoculated and incubated in standard temperature and environmental conditions, following manufacturer's recommendations. A parallel set of plates was inoculated and allowed to develop at ambient temperature for a longer duration, comparable to the environmental conditions frequently found in EWB project locations within developing regions. The ambient set of testing plates provided comparable results to the incubated set of testing plates. For the purposes of identifying scale of water contamination in regions where standard testing facilities and/or equipment are not available, this approach to testing plate incubation for water biological contaminants may potentially simplify procedures for a range of EWB water projects.