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problems of ground instability for construction purposes. This makes it infeasible to excavate to depths appropriate for conventional sewer systems. |
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3. Water shortage. The lack of water is a problem faced by the island as a whole. Every house has a water tank for collecting rainwater, which is used for cooking and drinking. Although the water network of Oia has expanded in recent years, there is insufficient water during the tourist season. Therefore tankers are still used to bring water from boreholes in the middle of the island by road. The proposed construction of a desalination plant for the Oia Community is expected to solve the problem. |
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4. Topography. Finikia has grown up alongside three drainage basins from south to north. The slopes have a high average gradient, ranging from 15 to 25 per cent. The three basins (here referred to as A, B and C) are dry all year round, as rainwater percolates immediately because of the soil type. |
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5. Lack of final disposal. A number of houses have septic tanks. However, because these are not emptied sufficiently frequently, they often overflow. The majority of the houses rely on infiltration pits, which remains a restricted disposal method. |
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These and other factors were taken into consideration to help determine an appropriate design for the low-cost sewerage system. The local Community Council was consulted, as was the community's technician. It was also important to take into account the impact on the new system of the proposed development of a number of hotel complexes. |
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6.3
Design Considerations |
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6.3.1
Conventional Design |
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In Greece the design of conventional sewerage systems is subject to the compulsory guidelines contained in Law 696/1974. These guidelines are considered conservative and their implementation can lead to very poor hydraulic behaviour of sewers in small |
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