3.4.4 Equipment capability and maintenance

Summary of actions

• Ensure that equipment performs adequately and provides sufficient flexibility and process control.

• Establish a program for regular inspection and maintenance of all equipment, including monitoring equipment.

The capability of equipment is an important consideration in maintaining process control. Equipment and infrastructure in a drinking water supply system need to be adequately designed and of sufficient capacity (size, volume, detention times) to handle all flow rates (peak and otherwise) without limiting performance. Processes should not be hydraulically overloaded or subjected to rapid changes in hydraulic loading, as these conditions may compromise performance.

Design features that can improve performance and process control include:

• online measuring devices that monitor operational parameters continuously;

• automated responses to changes in water quality;

• 24-hour monitored alarm systems that indicate operational failure;

• backup equipment, including power generators;

• variable control of flow rates and chemical dosing;

• effective mixing facilities.

Design of new equipment and processes should undergo validation through appropriate research and development (see Section 3.9.).

Equipment used to monitor process performance should also be selected carefully. Monitoring equipment needs to be sufficiently accurate and sensitive to perform at the levels required. Wherever possible, monitoring should be online and continuous, with alarm systems to indicate when operational criteria have been exceeded. Monitoring failures should not compromise the system and in some cases, particularly at critical control points, backup equipment should be considered.

Staff should understand the operation of monitoring equipment so that causes of spurious results can be recognised and rectified.

Regular inspection and maintenance of all equipment from catchment to consumer is required to ensure continuing process capability. A maintenance program should be established and documented, detailing:

• operational procedures and records for the maintenance of equipment, including the calibration of monitoring equipment;

• schedules and timelines;

• responsibilities;

• resource requirements.