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Engineered Design Solution for Site with Sanitation System Problems/Challenges
Water and Sanitation III is a mandatory and core component of the Advanced Diploma in Civil Engineering. Water and Sanitation III is an exit-level module for this qualification. This module aims to enhance students’ competencies and skills in addressing a wide range of groundwater problems, rainfall and surface runoff, flood analysis, hydrological modelling, fluvial hydraulics (sediment transport), design parameters for reticulation systems, distribution components and ancillary works, stormwater networks, wastewater networks, and pumping installations (Unisa, 2024).
Project Bried: Sanitation System Design
The selection of an appropriate sanitation solution is important for ensuring public health, environmental protection, and sustainable development. Site-specific factors such as population density, soil permeability, groundwater levels, topography, and financial resources have a significant influence on the choice between sewered systems, decentralized wastewater treatment, or on-site sanitation options (Tilley et al., 2014).
In South African urban centres, conventional waterborne sewerage is common but often limited by ageing infrastructure, water scarcity, and high maintenance costs (DWS, 2016). Consequently, in rural areas, decentralized systems such as small-scale wastewater treatment plants, septic tanks, and ventilated improved pit (VIP) latrines are widely used due to their lower capital costs and adaptability to challenging site conditions (DWAF, 2008; Still & Foxon, 2012). However, poor operation and maintenance of these systems have led to environmental degradation and health risks in some regions. Therefore, selecting an appropriate sanitation solution in South Africa requires careful consideration of local site conditions, community needs, and long-term sustainability to meet both national service delivery targets and the Sustainable Development Goals (SDGs) (RSA, 2016; WHO, 2018).
Student task:
As a Water and Sanitation Engineering student, you are tasked with identifying a site with sanitation system problems/challenges (this can be supported by a literature review and/or photos) and proposing an engineered design solution.
Your designs should address the following (but not limited to):
- Your design should accommodate 200 houses (it can be in a rural or urban, dwelling setting of your choice with 200 houses).
- Select an appropriate sanitation solution based on site conditions (e.g., sewered system, decentralised wastewater treatment, or on-site sanitation like septic tanks or VIP latrines).
- Design sewage collection and conveyance system, including pipeline layout, manholes, and pump stations (if needed) using CAD or any relevant drawing software (No freehand layouts).
- The layout should reflect the number of your houses corresponding to your hydraulic designs.
- The layout must be your own work, corresponding to the supporting stats/images of the identified problem.
- Locate and propose a treatment method (e.g., oxidation ponds, biofiltration, or wetlands).
- Conduct hydraulic analysis of sewer flows, pipe slopes, and capacity.
- All design calculations must be shown.
- Your input assumptions must be guided by standards/codes.
- Use appropriate software for simulations/analysis.
- Develop a layout plan for wastewater infrastructure, ensuring compliance with environmental regulations, including inspection manholes.
- Use relevant standards (for example, Human Settlement Red book, drainage manual, and others).
Environmental & Sustainability Considerations
- Assess the impact of the water and sanitation system on local water resources.
- Propose sanitation solutions that minimise groundwater contamination and align with public health requirements.
Expert Answer on Above Civil Engineering Questions
Site identification: The site that is selected for the purpose of analysis is Ga-Mashashane Village, Limpopo. This site has been selected which is located in Polokwane Local Municipality and it is faced with inadequate sanitation infrastructure problems. The issue is mainly identified in the dense area and there is no sewage network which led to the problem. There are many challenges identified because of inadequate infrastructure and these include:
1) high groundwater risk contamination from pit latrines.
2) there is limited municipal service coverage.
3) residents are highly dependent on VIP toilets.
4) absence of sewer treatment facilities.
Selected sanitation solution: The sanitation solution that is selected is a decentralized wastewater treatment with septic tanks along with anaerobic baffled reactor. This solution is highly justified because it is financially feasible, and there are moderate slopes which allow for supportive gravity flow.
| Disclaimer: This answer is a model for study and reference purposes only. Please do not submit it as your own work. |
