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the objectives involved. For sewerage operations and maintenance in Ghana, typical aims are: |
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to comply with safety and public health requirements; |
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to ensure that the best operational knowledge and experience is utilized whenever practical in the design of new works; |
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to ensure that all work is carried out in the most cost-effective manner; |
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to ensure the integrity of each element of the sewerage system; |
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to minimize nuisance from odours and noise; |
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to ensure that failure of any part of the sewer scheme has the minimum effect on the rest of the system; and |
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to ensure that only authorized persons enter or work on the sewer system. |
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5.4.2
Plannng a Maintenance Strategy |
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The size of a typical simplified sewerage system makes it infeasible and uneconomic to give frequent attention to all sewer lines. In spite of this general lack of maintenance, many simplified sewers continue to function adequately and do not give rise to problems. Because of this, there is great scope for introducing a system of inspection and maintenance that identifies only those parts of the system which justify attention on a predetermined programmed basis, leaving the remainder to be dealt with only on a reactive basis. Often in developing countries, only a small minority of the sewerage system should be dealt with on a planned basis. |
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Reactive or crisis maintenance involves responding to failures and problems as they occur. In the less sensitive parts of the simplified sewerage system, where failures or problems do not have severe consequences, reactive maintenance is the most appropriate system because it will generally be cost effective. In contrast, planned maintenance involves undertaking inspections, and carrying out maintenance in order to reduce frequency or risk of failure. If it does not achieve these objectives, then the additional expense of planned maintenance cannot be justified. It must give 'value for money' to the sewerage operator. |
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