Prof. Dr. Abdelsalam Elawwad (أ.د. عبد السلام العواد)

Leakage in sewerage system can cause groundwater and soil contamination in urban areas, especially in area with a high groundwater table. This is a serious problem in small agricultural villages which rely on ground water as a source for irrigation and drinking purposes. In the developed countries, the recent trend in areas with low population densities is using vacuum sewerage system. Vacuum system could be environmentally safer than conventional gravity system, protecting public health, preventing exfiltration to the ground water, very easily applied in a relatively short time, and can cope with a faster expansion of the urbanized areas. Detailed hydraulic design were held for both gravity sewer and vacuum sewer systems in 28 Egyptian agricultural villages as a case study for developing regions. Different conditions, such as population, areas, and terrain slopes were evaluated. Cost comparisons based on statistical analysis were done to assess the feasibility of using vacuum sewerage in developing regions. Based on this study, from financial point of view, vacuum sewerage system was a good competitor to conventional systems in flat areas and areas with high groundwater table. From the environmental point of view, it is recommended to construct the vacuum sewerage system in such agricultural villages. The local market supplying of the construction equipment especially collection chambers will greatly affect the investment cost. Capacity building and social mobilization will also play a great role in sustainability of this system.