In Study Session 8, on Water Safety Plans, you learned how important it was to identify the hazards in a water supply system and to carry out a risk assessment so that control measures could be put in place to protect water quality. In this study session you focus on sanitary inspections as a means of identifying the hazards at a water source. Doing this at source is the most effective way of safeguarding consumers. A sanitary inspection (in this context) is a survey of the surroundings of a water source to identify possible health hazards and sources of pollution. Unlike in the development of a Water Safety Plan, sanitary inspections can be undertaken by individuals, often called sanitary technicians, who consider the water source, the sources of contaminants, and water handling by household members. Information is gathered by observation and by making enquiries of the residents and household members living near to the water sources. Sanitary inspections, sometimes referred to as ‘sanitary surveys’, play a vital part in preventing contamination of water supply systems.
One factor to consider is the time of year. The season will affect the quality of water sources. For instance, during the rainy season, rainwater run-off is likely to carry pollutants such as faecal matter from the surface of the ground into rivers. The pollutants may also be carried into groundwater by water percolating into the ground and thus lead to contamination of well and spring waters.
Duties of a sanitary technician
Carrying out inspections, recording data and, importantly, any follow-up with further analysis are important functions of the sanitary technician. In many parts of the world, the sanitary technician reports to a District Water Surveillance Coordinator or similar position. The duties of a sanitary technician might include the following:
- carrying out routine (for instance, weekly) monitoring of water sources and distribution systems
- checking and recording chlorine residuals on the spot, and sampling from sites showing low levels (such as 0.1 mg l–1 free chlorine) for bacteriological analysis
- transporting samples to the appropriate laboratory
- entering analytical results in surveillance reports and submitting weekly reports to the District Water Surveillance Coordinator
- informing the Water Surveillance Coordinator of high-risk zones – such as those where water pressure is low, leakage high, the results of bacteriological tests bad or standpipes are used – as soon as they are identified, and indicating by appropriate means any advice to be given to the community in an emergency
- intensifying the monitoring of high-risk water supply zones
- carrying out special sampling programmes in peri-urban and urban areas unserved by piped systems and preparing reports on them
- periodically providing samples to the provincial laboratory for chemical analysis and obtaining the results for inclusion in the district archive
- maintaining a register of all major sources of pollution of water resources and carrying out periodic inspections of these resources
- taking samples of water from urban water sources and sending them to the appropriate laboratory for full analysis
- keeping and updating an inventory of all water sources and their location, together with a sanitation inventory
- preparing a monthly summary of all sanitary inspections, including the advice provided on remedial action, and sending this summary to the District Water Surveillance Coordinator
- notifying the District Water Surveillance Coordinator of high-risk facilities, and requesting support from them for follow-up inspection and analysis.
There need to be standard procedures for carrying out sanitary inspections. In this study session you will consider three selected examples from WHO guidance to illustrate the principles and the sort of questions that are involved.