WATER QUALITY
How to test water quality? Low-cost, low-tech options for microbial testing. Microbial testing is arguably the most important factor when monitoring the quality of drinking water. Without noticing anything strange, a single glass of cool, refreshing water could contain billions of microorganisms. Just a few dozen of these organisms could be enough to make you very sick. [1] According to estimates from the World Health Organization, diarrheal disease from contaminated drinking water causes more than half a million deaths annually . [2] There are a large number of microbial testing options available today, but they are not perfect. Selective media and enzyme-based assays that detect E. coli ’s beta-glucuronidase enzyme are often well-suited for low-resource settings. [4] Overall, these microbial water quality tests take one of three approaches: Presence-absence (P-A) : P-A tests don’t provide quantitative information about microbial water quality. Instead, they change color to te
