Lecture (7): Topic (1) Types of site sanitation ways : On-site sanitation systems Small-piped sewerage system Conventional sewerage system :

On-site sanitation systems are widely used in rural areas of both developed and developing countries. in the absence of more costly sewerage system. Include different designs like ventilated improved pit latrine, pour-flush single and double pit latrines, septic tanks … etc.

Small-piped sewerage system These are technologies, such as simplified sewerage systems used by multiple plots that collect wastewater and excreta produced at neighborhood level or from several houses.

Conventional sewerage system : There are two type in this system: Combined sewers system . Separated Sewers system. (go back Environmental Health course in Third year)

Chain Pros Cons On-site sanitation - Low investment costs; - Can be constructed and repaired using locally available materials Techniques can be mastered locally (they don’t require great technical expertise); Not necessary to have a constant water source. Costs of emptying; health risks linked to sludge if this is not sanitized; - Risk of underground pollution.

Chain Pros Cons Small-piped sewerage system - Medium-level operation and maintenance costs; - Very convenient; - Extension possible should the population evolve; - Permanent evacuation of pollution far from the population’s place of residence. - Design and construction requires expert intervention; - Qualified labor required for care and maintenance.

Chain Pros Cons Conventional sewerage system - Highly convenient; - Long lifespan of the system; - Permanent evacuation of pollution far from the population’s place of residence; - Adapted for areas of high population density and where large volumes of wastewater are produced Very high investment costs; - Design and construction requires high-level expert intervention; - Qualified labor required for care and maintenance.

feasibility technical solution criteria: Acceptance by (households + professionals). Lifespan of the infrastructure. The efficiency of the service put in place. Investment and operating cost. Design, construction and care and maintenance . Accessibility. Electrical energy. Required surface area. Water requirements.

Factors to consider when choosing a sanitation system The initial cost and the costs of O&M; Demand and use. Climate (temperature, humidity and rainfall); Soil and topography Water availability (for waterborne systems); 6. Cultural beliefs, values and practices Availability of technical skills Agriculture

Quiz Quiz (1): Mentioned five Factors to consider when choosing a sanitation system: ……. …… …..

Quiz (2): Factor not to be consider when choosing a sanitation system. Demand and use. Climate. Soil and topography . Water availability. Family size.

Chain Pros Cons On-site sanitation ………………….. ……………………

Conventional sewerage system Chain Pros Cons Conventional sewerage system ………………….. ……………………