Sanitation Systems

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Sanitation Systems

• Issues for Consideration

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To remember before we start on technology

• Remember not just for the adults
• Very context specific
• Large number of taboos and difficulties in
  researching defecation behavior
• Few people care about sanitation

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Waste to be managed

• Managing human and animal excreta
• Solid waste management
• run-off drainage

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Sanitation of human excreta

• Why
• Minimize risk of disease transmission
• Ease and privacy to users
• Reduce nutrient pollution to the environment
• Recycle nutrients of value to agriculture or fish
  production
• Reducing smell and files
• Managing a by product (150g-500g faeces and 1l to
  1.5l of urine per day)

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Excreta Disposal

• For a sanitation facility to protect public
  health it needs to (Carr and Strauss 2002)
• Isolate the user from their own excreta
• Isolate communities from exposure to excreta
  (e.g. through contaminated drinking water)
• Prevent nuisance animals (e.g. flies) from
  contacting the excreta and subsequently
  transmitting disease to humans
• Contain the excreta and/or inactivate the
  pathogens.

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Sanitation of Human Excreta

• Decomposition process
• anaerobic
• aerobic

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Classification of Sanitation Systems

• on site/off site
• wet/dry
• permeable/confined

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Classification of Sanitation Systems

• on-site systems in which safe disposal of
  excreta takes place on or near the housing plot
  pit latrines and septic tanks fall into this
  category.
• Some on-site systems, particularly in densely
  populated regions, require off-site treatment
  components as well. For example, the faecal
  sludges accumulating in single pit or vault
  latrines in urban areas and in septic tanks
  periodically need to be removed and treated
  off-site for use or disposal
• Off-site systems in which excreta are collected
  from individual houses and carried away from the
  plot to be disposed of sewerage is the most
  important option in this category.

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On Site Sanitation

• Show graphs

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On Site Sanitation

• With respect to a simple pit latrine or a VIP pit
  latrine discuss advantages /disadvantages
• protection of population from transmission?
• cost, maintenance and management?
• Social, gender and cultural aspects?
• Soil and water aspects?

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On Site Sanitation - Pit Latrine

• Relatively low cost and limited organizational
  capacity needed
• Superstructure can be made from locally available
  materials and by household members
• Slaps may require inputs from outside
• Superstructure affords privacy to the user and
  can be made child friendly
• Design and location determines use
• Relatively safe disposal into a hole and limited
  occupational risk
• Because of the long storage time in the pit,
  disease-causing organisms (pathogens) are
  eventually killed
• Relatively small volume of water used
• Liquid is allowed to seep from the pit into the
  surrounding ground but may results in local
  contamination of water sources
• In the pit, excreta undergoes decomposition into
  humus-like solids, water, and gases

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Problems with - Pit latrines?

• Pit latrines are smelly and attract flies?
• Pit latrines cannot be used on small plots?
• On-site systems pollute groundwater?

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Communal Sanitation Facilities

• With respect to communal pit latrines discuss
  advantages/disadvantages
• protection of population from transmission?
• cost, maintenance and management?
• Social, gender and cultural aspects?
• Soil and water aspects?

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On Site Sanitation - Septic tank

• Show graphs

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On Site Sanitation - Septic tank

• With respect to septic tanks discuss
  advantages/disadvantages
• protection of population from transmission?
• cost, maintenance and management?
• Social, gender and cultural aspects?
• Soil and water aspects?

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On Site Sanitation - Septic tank

• Relatively expensive
• Comprises a sealed tank having both an inlet and
  an outlet into which excreta are flushed from a
  conventional cistern flush toilet.
• In the tank, solids settle out and undergo a
  process of anaerobic decomposition resulting in
  the production of water, gases, sludge, and a
  layer of floating scum.
• The effluent which flows out of the septic tank
  is commonly disposed of through absorption into
  the ground using a soakage pit or trench (may
  require a large area of land).

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Off Site Sanitation

• With respect to simplified sewerage discuss
  advantages/disadvantages
• protection of population from transmission?
• cost, maintenance and management?
• waste treatment?
• Social, gender and cultural aspects?
• Soil and water aspects?

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Approaches to sanitation promotion

• Identifying key target groups to be reached
• Identifying core messages to be communicated
• Awareness of the prevailing socio-cultural
  framework, to understand what motivates people to
  invest
• Consideration of sanitation as a consumer good,
  not just as a potential health benefit
• Use a mix of communication methods, with simple
  language and clear messages
• Identify cost-effective means of communication
• Encourage the widest possible stakeholder
  participation
• Promote only appropriate technology (including
  gender and cost considerations)
• Consider demand based approaches

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Demand based approach

• Demand based approaches focus on what people
  want, but are limited by what they know. Two
  steps to be taken
• Establish demand assessments need to be made to
  see whether households want improved sanitation
  where people do not show through their actions
  that they want sanitation it will be necessary to
  stimulate demand through promotion campaigns
• Inform demand demand may not be realistic once
  it has been established. Potential users may have
  an incomplete understanding of options open to
  them, the likely costs and benefits. Unrealistic
  expectations about who pays for the desired
  service will also need to be addressed.