9.2 Monitoring overview

The Framework encourages a considered, overall strategy for monitoring that includes:

• operational monitoring in the source/catchment, through the treatment process, and in the distribution system, to ensure that processes and activities are functioning optimally to achieve safe drinking water;

• verification of drinking water quality, which consists of:

  • drinking water quality monitoring in the distribution system to verify the quality of treated water as supplied to the consumer; and

  • consumer satisfaction monitoring to assess consumer comments and complaints;

• investigative studies and research monitoring (including baseline monitoring where new water sources are going to be used to supply drinking water) to identify and characterise hazards, and increase understanding of a water supply system;

• validation monitoring of new operational processes and barriers, to assure effective operation and control; and

• incident and emergency response monitoring, undertaken in response to incidents or emergencies.

Each type of monitoring supports the others in the overall understanding and management of a water supply system, and in interpreting the monitoring data that are generated.

The overall goal of monitoring is to provide a high level of public health protection by minimising the risk of supplying contaminated drinking water. Water suppliers therefore need to ensure that monitoring attention and resources are directed to those aspects that provide the greatest assurance of drinking water quality.

Monitoring programs that focus primarily on the quality of treated drinking water do not effectively guarantee the supply of safe drinking water. Event-driven, intermittent contamination or system failures (characteristic of failures in the developed world) are very difficult to recognise and control through the monitoring of treated drinking water quality alone. In addition, the results of such monitoring do not become available until after the drinking water has been supplied to customers.

Developing a monitoring program is not a static activity, but part of an ongoing, iterative process of system management that seeks to understand the challenges and risks, plan and implement measures to prevent contamination (appropriate to the level of risk), monitor and assess the effectiveness of these barriers, plan improvements, and adjust preventive measures and monitoring programs as required. This approach is summarised in Figure 9.1.

Figure 9.1 Monitoring as part of an ongoing process of system management

The following sections of this chapter describe important principles and elements of a strategic monitoring system for assuring drinking water safety.