Field Study of Real-Time Water Quality Control

Abstract

The objective of a drinking water network is to provide a good quality of water to users. Accidental or intentional contamination can degrade the water quality and consequently threats the consumer's health. Generally, the water quality is monitored using traditional methods, based on manual sampling, which can take several days. Early warning of water contamination can be achieved using smart technology. This paper presents a field study of the use of this technology in real-time monitoring of the water quality. The field study is conducted at the Campus of the University of Lille in the North of France within the European Project "SmartWater4Europe" (http://www.sw4eu.com). Two sensors are installed in the campus: S::CAN and EventLab which measure several water quality parameters such as TOC (Total Organic Carbon), turbidity, refractive index, etc. This paper presents analysis of these parameters as well as the influence of hydraulic parameters on the water quality. It presents also an event detection system, which is developed using CANARY software. A sensitivity study is presented to determine the appropriate parameters in order to reduce false alarms and to determine the probability of possible event.Keywords: water quality, monitoring, event detection, smart technology. INTRODUCTIONThe main objective of the water supply is to ensure a safe drinking water for consumers. Water distribution system (WDS) can be subjected to accidental contamination or malicious attack which can affect the water quality. Although treatment works are closely monitored and controlled in the developed countries, this is not the case for all less developed countries. Many factors such as backflow, pipes break, physico-chemical and biological reactions and corrosion, can induce the deterioration of water quality.In order to protect public health from contamination events, water utilities are concerned by a real-time monitoring of the water quality. In general, water quality control is based on taking manual samples in a periodic basis, and then doing several laboratory analyses: i) physico-chemical to determine organoleptic characteristics of tested water; and ii) microbiological to identify the presence of pathogenic microorganisms. These traditional methods can take from several hours to some days.Contamination could occur in WDS and causes serious diseases. Recently, a contamination by industrial chemical (MCHM) occurred in the distribution networks of Charleston, West Virginia (USA) and affected more than 300,000 consumers [1].In order to prevent contamination events earlier and to protect the water network from any intrusion, water companies could use smart technology, which allow a rapid detection of abnormal events. On-line water quality sensors can be used to enhance the monitoring of the water quality in real-time [2]. According to a recent survey by Walsby [3], the smart technology could lead to high savings in water industry (between 7.1 and 12.5 billion US$ per year). The use of the smart technology in real-time m...