In-Situ Water Quality Monitoring for Resource-Constrained Areas

Abstract

Water-borne pathogens and unsafe water supplies are the cause of death for 1.7 million people every year [1]. Many of these people live in the developing world, where it can be difficult to manage water safety. The World Health Organization mandates that many countries use standardized water quality measurements, and these measurements can take up to 18 hours and require unsustainable equipment and trained operators [2]. Fluorometers provide real-time prediction of both presence and number of thermotolerant (faecal) coliforms (TTCs) in water samples. This makes a fluorimeter an ideal water quality measuring device that would reduce the large amount of time required for water testing by current WHO standards [3]. However, current fluorometers are extremely expensive and not sustainable for in-field use. We present a low-cost fluorometer that will passively and accurately collect real time water quality measurements. Our device measures a fluorescent signal called tryptophan-like fluorescence (TLF), which is produced by bacteria when exposed to light at a specific frequency. This device exploits this phenomenon to deduce the quantity of bacteria in the sample. We hypothesize that this device will have accuracy that matches the current WHO standards for water quality measurements, and will be cheaper, easier to use, and more sustainable than the current methods.