ON –SITE SANITATION
SIZIVA TICHAONA N02018831P
SAMUKELE P NYONI N02160343W
TALENT SIBANDA N02022009J
DOUBT HLABANGANA N02022115B
KUNAISHE KUSAKASA N0188732Q
PRINCE K MUNSAKA N0176500X
KUDZAI MUKANDIDZE N0198782F
INTRODUCTION
• Onsite sanitation is defined as the proper treatment of wastewater at the point of generation it is also known as
Decentralized wastewater treatment system.
• The system can be aerobic or anaerobic depending on designs
• Most of these, value water re use on site and limits the need of external processes (centralized )
• On average onsite minimise energy demand in both ways (processing or installations)
• Time rresource saver- period of assembling the system is less than of offsite management
TYPES OF ONSITE
1 Biogas
2 Septic tanks
3 Aquaprivies
4 Pit latrines
5 Ventilated Pit Latrines
8 Continuous Composting Toilets
9 Septic Tank Latrines
MERITS OF ONSITE SANITATION SYSTEMS
• Decentralized Treatment
• Water Conservation
• Reduced Energy Consumption
• Lower Costs
• Increased Flexibility
• Improved Public Health
• Environmental Protection
• Reduced Infrastructure Requirements
• Increased Reliability
DEMERITS OF ONSITE SANITATION SYSTEMS
• Higher Maintenance Requirements
• Limited Treatment Capacity
• Aesthetics and Odors
• Pathogen and Vector Risks
• High Upfront Costs
• Requires User Education
• Space Requirements
• Sludge Management
• Regulatory Compliance
AQUAPRIVY
• Suitable for household and commercial sites
• Processes toilet waste and household sullage
• More odourless than all other pit latrines
• Durable to serve a long time
• Requires minimal water supply
• Low Maintenance costs
ADVANTAGES AND DISADVANTAGES
Advantages: Disadvantages:
1. Suitable for Various Sites 1. Higher Upfront Costs
2. Processes Various Wastes 2. Requires Regular Emptying
3. More Odourless 3. Limited Capacity
4. Durable 4. Dependence on Proper Use
5. Minimal Water Supply Required 5. Potential for Clogging
6. Low Maintenance Costs
SEPTIC TANKS
• The system contains various tanks to improve settlement of sludge
• These are water tight tanks that allows accumulation of sludge within a specified period
• Have at least three compartments
• Desludging must be done accordingly
• The system links to a soak away
• Requires minimal maintenance schedules
FUNCTIONAL SEPTIC SYSTEM
ADVANTAGES
Advantages: Disadvantages:
1. Effective Sludge Settlement 1. Requires Regular Desludging
2. Low Maintenance Requirements 2. Limited Treatment Capacity
3. Reliable and Efficient Treatment 3. Odor and Aesthetic Issues
4. Reduced Environmental Impact 4. Groundwater Contamination Risk
5. Cost-Effective Solution 5. Soil Saturation and System Failure
6. High Upfront Installation Costs
BIOGAS SYSTEM
• Characteristics:
• Temperature Range: 25-40°C
• pH Range: 6.5-8.5
• Retention Time: 10-30 days
• Biogas Production Rate: 0.2-0.5 m³/kg of organic matter
• Organic Loading Rate: 0.5-2.0 kg/m³/day
• Hydraulic Retention Time: 10-30 days
• Solids Retention Time: 30-60 days
• Gas Composition: 50-70% methane, 30-50% carbon dioxide
• System Size: 1-100 m³
• Material Requirements: Concrete, steel, PVC pipes and fittings
ADVANTAGES AND DISADVANTAGES
Advantages: Disadvantages:
1. Renewable Energy Source 1. High Initial Investment
2. Waste Management Solution 2. Space Requirements
3. Versatile 3. Maintenance Requirements
4. Low Operating Costs 4. Odor and Aesthetic Issues
5. Environmentally Friendly 5. Safety Concerns
URINARY DIVERTING DRY TOILETS
Characteristics:
• Have two or three chambers which will be used in rotation
• Solid feacal matter and liquids (urine) are separated
• Easy to use and maintain
• Requires speciality to install
• Non water dependent
• Safe and clean to the environment
ADVANTAGES AND DISADVANTAGES
Advantages: Disadvantages:
1. Water Conservation 1. Requires Specialized Installation
2. Easy to Use and Maintain 2. Higher Upfront Costs
3. Non-Water Dependent 3. Requires User Education and Training
4. Safe and Clean for the Environment 4. Limited Availability of Replacement Parts
5. Reduces Waste Volume 5. Aesthetically Unpleasant for Some Users
6. Promotes Sustainable Sanitation
PIT LATRINES
Characteristics:
• Depth: 1-3 meters
• Width and Length: 1-2 meters
• Shape: Circular, rectangular, or square
• Slab Material: Concrete, wood, or metal
• Seat Type: Squatting plate or pedestal seat
• Superstructure Material: Wood, metal, or thatch
ADVANTAGES AND DISADVANTAGES
Advantages: Disadvantages:
1. Limited Capacity
1. Simple to Install
2. Requires Little Maintenance 2. Can be Unhygienic if Not Properly Maintained
3. Suitable for Homesteads and Rural Areas 3. Attracts Flies and Other Disease-Carrying Insects
4. Cheap to Maintain 4. Can Contaminate Groundwater
5. Easy to Use 5. Requires Regular Emptying
6. Low Construction Costs 6. Can be Aesthetically Unpleasant
7. Can be Built with Local Materials 7. May Not Meet Modern Sanitation Standards
VENTILATED IMPROVED PIT (VIP) LATRINES
Characteristics:
• Depth: 1.5-3 meters
• Width and Length: 1-2 meters
• Shape: Circular, rectangular, or square
• Slab Material: Reinforced concrete
• Seat Type: Squatting plate or pedestal seat
• Ventilation Pipe Diameter: 10-20 cm
• Ventilation Pipe Height: 1-2 meters above the roof
• Superstructure Material: Wood, metal, or concrete blocks
ADVANTAGES AND DISADVANTAGES
Disadvantages:
Advantages:
1. Reduces Odors and Fly Nuisance 1. Requires Regular Maintenance of Vent Pipe
2. Improved Ventilation and Air Quality 2. Can be Affected by Weather Conditions (e.g. Wind, Rain)
3. Reduces Disease Transmission 3. May Not Completely Eliminate Odors
4. Low Maintenance Costs 4. Requires Proper Installation and Construction
5. Simple and Cost-Effective to Install 5. Can be More Expensive than Traditional Pit Latrines
6. Can be Used in Areas with High Water Tables 6. May Not be Suitable for Areas with High Population Density
CONTINUOUS COMPOSTING TOILETS
o Continuous Composting Toilets (CCTs) are a type of dry toilet
that uses natural processes to decompose human waste into a
nutrient-rich compost
o Key Components:
• Toilet Chamber
• Carbon-Rich Materials
• Aeration System
• Composting Chamber
• Moisture Control
CONTINUOUS COMPOSTING TOILETS
Characteristics:
• Depth: The composting chamber can be 1-2 meters deep.
• Width and Length: The composting chamber can be 1-2 meters wide and 2-3 meters long.
• Shape: The composting chamber can be rectangular, square, or circular.
• Materials: The toilet chamber and composting chamber can be made of concrete, plastic, or metal.
• Capacity: CCTs can serve 1-10 users, depending on the design and size.
ADVANTAGES AND DISADVANTAGES
Advantages: Disadvantages:
1. Higher Upfront Costs 1. Higher Upfront Costs
2. Requires Regular Maintenance and Monitoring 2. Requires Regular Maintenance and Monitoring
3. Can be Aesthetically Unpleasant 3. Can be Aesthetically Unpleasant
4. May Attract Pests and Insects 4. May Attract Pests and Insects
5. Requires Proper Carbon-to-Nitrogen Ratio Management 5. Requires Proper Carbon-to-Nitrogen Ratio Management
6. Can Produce Unpleasant Odors if Not Maintained Properly 6. Can Produce Unpleasant Odors if Not Maintained Proper
INCINERATION
• Incinerate the accumulated waste
• The residue ashes are used as manure or any use necessary
• Typically safe to the environment at large
• Maintained on-site once or regularly if need be
• Limits water use
ADVANTAGES AND DISADVANTAGES
Advantages: Disadvantages:
1. Reduces Waste Volume 1. High Initial Investment for Incinerator
2. Typically Safe for the Environment 2. Energy Consumption for Incineration
3. Residue Ashes Can be Used as Manure 3. Requires Regular Maintenance and Monitoring
4. Maintained On-Site 4. Can Produce Air Pollution if Not Properly Managed
5. Limits Water Use 5. Requires Proper Ash Disposal
6. Effective for Pathogen Destruction 6. May Not be Suitable for Large-Scale Waste Management
7. Reduces Odors and Pests 7. Can be Noisy and Produce Unpleasant Odors
CONCLUSION
• Onsite sanitation systems are a viable and effective solution for managing wastewater and excreta,
particularly in areas where centralized sewerage systems are not available or are inadequate.
Recommendations for Onsite Sanitation Systems:
1. Promote adoption in suitable areas.
2. Improve design and installation considering local conditions and user needs.
3. Regularly maintain systems to prevent risks.
4. Educate users on proper use and maintenance.
REFERENCES
1. World Health Organization. (2018) Guidelines for the safe use of wastewater, excreta and greywater. World Health
Organization, Geneva.
2. United States Environmental Protection Agency. (2019) Decentralized Wastewater Treatment Systems. United States
Environmental Protection Agency, Washington, D.C.
3. Water Environment Federation. (2019) Onsite Wastewater Treatment Systems. Water Environment Federation, Alexandria,
VA.
4. American Society of Civil Engineers. (2018) Standard Practice for the Design and Installation of Onsite Wastewater
Treatment Systems. American Society of Civil Engineers, Reston, VA.
5. National Environmental Services Center. (2019) Onsite Wastewater Treatment Systems: A Guide to Planning, Design, and
Operation. National Environmental Services Center, Morgantown, WV.
6. International Water Association. (2018) Onsite Wastewater Treatment and Reuse. International Water Association, London.
7. Centers for Disease Control and Prevention. (2019) Water, Sanitation, and Hygiene (WASH) and Onsite Wastewater
Treatment Systems. Centers for Disease Control and Prevention, Atlanta, GA.
