Design and Experimental Evaluation of an IOT-Enabled Multi-Parameter Water Quality Monitoring System

In recent times access to safe drinking water remains a critical health priority at the global scale with several illness being linked primarily to the source of water we consume. Unlike conventional approaches of evaluating the quality of water which often involves collecting sample and taking it to laboratories. The emergence of Internet of Things (IOT) now makes it possible for a low-cost, real-time and on-site water quality test. This paper presents the design and experimental evaluation of a multi-parameter water quality monitoring system built utilizing the ESP32 microcontroller. The system integrates four primary sensors; a temperature sensor probe, pH sensor, Total Dissolved Solids (TDS)/electrical conductivity sensor and a turbidity sensor to evaluate water quality in real-time. Sensor readings are then displayed on a 0.96-inch OLED display and streamed over Wi-Fi to an Arduino Cloud dashboard where various widgets provide real-time visualization of data. An on-board classification algorithm compares each reading against the World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ) acceptable parameter readings and reports a SAFE/UNSAFE verdict. The system was evaluated using two water sources: commercially packed water (Sachet water) and untreated borehole water which most people living in this part of the world primarily consume daily. Results showed a slight variation in the pH and TDS of water across different water packaging company while they both still consistently maintain the NSDWQ threshold for all four parameters, while the borehole water exhibited significantly higher TDS and turbidity values which might be due to soil content, with pH occasionally falling below the recommended range. Correlation analysis between the temperature and the borehole readings were found to be a weak to moderate strength indicating the need for a multi-parameter setup as one parameter is not sufficient enough to make timely and informed decisions regarding safe drinking water.