|Key findings of the survey are summarised below.
Indicators that were identified for monitoring over time to determine the
real impacts of the project, are highlighted.
The results of the social survey and additional group interviews with women formed the basis for an awareness raising and hygiene education campaign. A separate door-to-door survey, to discuss the proposed scheme and household connections, was carried out.
CONSTRUCTION OF THE SANITATION SYSTEM
A survey was done using a theodolite to determine the topographic variations over the village. A plan with contour elevations was prepared and subsequently used as the basis for designing the sanitary drainage system. The village slopes gently to the east with a maximum elevation difference of 6 metres. The topography was suitable for gravity feed system similar to that installed by SEAM at Naga El-Deir village.
Design and Construction
It was proposed that Naga El-Karakra would be served by a simple, low cost sanitation system. The proposed gravity feed system would use buried sewage lines serving 115 households or around 60% of the population. Sewage would flow to two communal septic tanks at the eastern boundary of the village.
Detailed design was undertaken then checked and agreed with the Sohag Governorate Engineering Department. The following information was prepared and formed the basis of tender specifications:
|Companies were invited to tender for either a
turn key package for supply and installation, or to provide materials and
construction supervision with the villagers providing all necessary labour.
Following discussion with the Governorate and village unit the turn key
option was preferred and the works were awarded to a local contractor.
The collection system comprises five central gravity sewage pipelines. The network was designed to follow ground levels and minimise excavation depths for pipes and manholes. PVC pipes were selected for their ease of installation and lower cost. The diameter of the main pipelines varied from 6-8 inch, while 4 inch pipe was used for household connections. Manholes, or inspection chambers were installed and capped with cast iron covers. 115 households were connected.
Two in-series septic tanks were installed with a capacity of 100 m3. The septic tanks will work as a ‘primary/secondary’ treatment facility. Suspended solids will settle to the tank bottom. In addition, the septic tanks will allow for some secondary treatment by retaining wastewater long enough for anaerobic decomposition. Sludge formed from decomposition will settle to the tank bottom and liquors will discharge into an irrigation ditch. Sludge will be removed 1-2 times per year depending on its rate of accumulation. The design rate is expected to be around 0.04 m3/capita/year.
Installation took 9 months. Delays occurred in
having to excavate carefully around buried telephone cables and water pipes,
the location of which was not always known. Household connections did not
commence till after all main lines and septic tanks had been installed
and fully checked. Main items of the scheme are summarised below.