16.1 Rationale for a sanitary survey
In Study Session 15 you learned that a sanitary survey is an evaluation of the physical environment to identify possible health hazards and sources of environmental contamination. The survey should include an inspection of the entire water system, including the water source, facilities, equipment, operation and maintenance. It can be a complex technical task if carried out at a detailed level and may require expert help but you can conduct an onsite survey of the key elements, which are the water source itself, sources of contaminants and water handling by household members. There are many different aspects to a sanitary survey and different questions to be answered, so having a checklist of the necessary items is a useful aid. Some example checklists are included later in this session.
There are several reasons for conducting sanitary surveys of drinking water. Sanitary surveys are a comprehensive inspection of the entire water delivery system from the source to the mouth and are, therefore, the best means of identifying potential problems and changes in the quality of drinking water. They play a fundamental role in ensuring that consistent and safe drinking water supply is provided to the community by identifying and correcting any deficiencies in the system, and helping to identify public health risks related to drinking water.
The benefits of a sanitary survey, therefore, are that they can:
- Assure the long-term quality and safety of drinking water.
- Help to protect public health.
- Reduce the risk of waterborne disease outbreaks.
- Help source protection.
After conducting a sanitary survey you will be able to describe the extent of problems and consider possible solutions, which will vary depending on the circumstances. You can discuss these with the community leaders, religious leaders and local administrators, and perhaps find a rapid solution, if it is controllable by you. If the problems are more difficult to handle, you can report to the experts who are working at the district level.
A sanitary survey or inspection is a relatively simple technique that depends on gathering information, principally by observation and also by making enquiries. A more detailed assessment of water quality would require chemical and microbiological analysis, which would need specialised equipment and qualified staff, and would be more expensive than a sanitary survey. Some analytical equipment is portable and can be taken to the site but other tests can only be done in a laboratory. The recommended tools for field use are a portable pH meter with digital readout, a hand-held colorimeter, portable spectrophotometer and residual chlorine test kit.