Monitoring drinking water quality

Drinking water supply and distribution systems around the world (a critical and interdependent component of a nation’s infrastructure) are vulnerable to both intentional and accidental contamination. Unusual water quality may serve as a warning of potential contamination. The available physico-chemical sensors utilize general water quality parameters, such as free chlorine, oxidation reduction potential (ORP), total organic carbon (TOC), turbidity, pH, dissolved oxygen, chloride, ammonia, nitrate to detect the contamination. Generally, one or more of these water quality parameters will change due to the injection of a contaminant. However, no single chemical sensor responds to all possible contaminants nor can they give any indication of the potential toxicity of complex mixtures.

TOXcontrol (biomonitor), online monitoring for water security

Historically, monitoring of drinking water quality has generally relied on the collection of spot (popularly known as “grab sampling”) water samples followed by extraction and laboratory-based instrumental analysis for both inorganic and organic pollutants. This approach provides a snapshot of the concentrations of analyzed chemicals at a single point in time and space, again giving little indication of the samples toxicity due to single or multiple contaminants. However, research during the last two decades has shown that considerable limitations are associated with spot sampling approaches for determining total pollutant concentration (Allan et al, 2007). To overcome the limitations of grab sampling techniques, online monitors are more and more of much interest for water security application. A variety of online chemical and in combination with the TOXcontrol (popularly known as biomonitor) are being used in distribution system water quality modeling applications and intake protection.