WSE3701
Assignment 2
Comprehensive Analysis
Due 16 July 2025
,WSE3701
Assessment 2: Comprehensive Response
Due date: 16 July 2025
Sanitation System Design for a 200-Household Rural South African Community
, South Africa remains challenged by gaps in safe sanitation: only ~84% of the population
has access to “improved” sanitation (flush sewer/septic or ventilated pit), leaving ~16%
underservedscielo.org.za. Achieving SDG 6 (safe water and sanitation for all) requires a
dramatic scale-up in sanitation provisionsdgs.un.orgscielo.org.za. This report develops
a site-specific sanitation design for a 200‐household (≈1,200-person) rural/peri-urban
community in Limpopo Province (average household size ≈6, typical for low-income SA
contexts). The design draws on South African standards (CSIR “Red Book” guidelines,
WRC manuals) and WHO recommendations. All assumptions, formulas and
calculations are shown, and key design choices are justified with literature citations.
Literature Review of Sanitation Technologies
Rural/peri-urban sanitation options span centralized sewers to on-site systems. Key
technologies include:
• Conventional Sewerage (Centralized WWTP): Traditional gravity sewers
conveying to a municipal WWTP. This provides high treatment levels but requires
expensive trunk mains, pumping (if terrain demands), and reliable energy. South
African design guides (e.g. WRC Waterborne Sanitation Design Guide) prescribe
design flows ~70 L/person·daywrc.org.za, full-flow velocities
≥0.6 m/slegacy.winnipeg.ca, and pipe diameters ≥250 mm in public
sewerslegacy.winnipeg.ca. However, many rural areas lack such infrastructure
and high water use.
• Decentralized Wastewater Treatment (DEWATS): Cluster-scale systems like
anaerobic baffled reactors (ABRs), UASB reactors, and lagoon/wetland trains at
village level. DEWATS combine primary treatment (e.g. tank or ABR) with
secondary polishing (constructed wetlands or ponds).
In South Africa, DEWATS prototypes (ABR + wetlands) have shown 75–90%
COD and pathogen removalscielo.org.zapubmed.ncbi.nlm.nih.gov. For example,
a demonstration ABR+wetland in eThekwini achieved >85% BOD and ~83% E.
coli removal, though further polishing (e.g. vertical-flow wetland) was needed for
Assignment 2
Comprehensive Analysis
Due 16 July 2025
,WSE3701
Assessment 2: Comprehensive Response
Due date: 16 July 2025
Sanitation System Design for a 200-Household Rural South African Community
, South Africa remains challenged by gaps in safe sanitation: only ~84% of the population
has access to “improved” sanitation (flush sewer/septic or ventilated pit), leaving ~16%
underservedscielo.org.za. Achieving SDG 6 (safe water and sanitation for all) requires a
dramatic scale-up in sanitation provisionsdgs.un.orgscielo.org.za. This report develops
a site-specific sanitation design for a 200‐household (≈1,200-person) rural/peri-urban
community in Limpopo Province (average household size ≈6, typical for low-income SA
contexts). The design draws on South African standards (CSIR “Red Book” guidelines,
WRC manuals) and WHO recommendations. All assumptions, formulas and
calculations are shown, and key design choices are justified with literature citations.
Literature Review of Sanitation Technologies
Rural/peri-urban sanitation options span centralized sewers to on-site systems. Key
technologies include:
• Conventional Sewerage (Centralized WWTP): Traditional gravity sewers
conveying to a municipal WWTP. This provides high treatment levels but requires
expensive trunk mains, pumping (if terrain demands), and reliable energy. South
African design guides (e.g. WRC Waterborne Sanitation Design Guide) prescribe
design flows ~70 L/person·daywrc.org.za, full-flow velocities
≥0.6 m/slegacy.winnipeg.ca, and pipe diameters ≥250 mm in public
sewerslegacy.winnipeg.ca. However, many rural areas lack such infrastructure
and high water use.
• Decentralized Wastewater Treatment (DEWATS): Cluster-scale systems like
anaerobic baffled reactors (ABRs), UASB reactors, and lagoon/wetland trains at
village level. DEWATS combine primary treatment (e.g. tank or ABR) with
secondary polishing (constructed wetlands or ponds).
In South Africa, DEWATS prototypes (ABR + wetlands) have shown 75–90%
COD and pathogen removalscielo.org.zapubmed.ncbi.nlm.nih.gov. For example,
a demonstration ABR+wetland in eThekwini achieved >85% BOD and ~83% E.
coli removal, though further polishing (e.g. vertical-flow wetland) was needed for
