Self-Assessment Questions (SAQs) for Study Session 5

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering these questions.

SAQ 5.1 (tests Learning Outcome 5.1)

Match the following words to their correct definitions.

Using the following two lists, match each numbered item with the correct letter.

  1. urine-diverting latrine

  2. biogas latrine

  3. improved latrine

  4. cistern-flush latrine

  5. ecosan latrine

  6. VIP latrine

  7. anaerobic digestion

  8. pour-flush latrine

  • a.a latrine where there is no contact between the user and the excreta produced

  • b.the process by which organic matter is decomposed by microorganisms in an environment where there is no air

  • c.a type of latrine that generates a fuel gas

  • d.a type of latrine where the faecal matter is composted

  • e.a type of toilet where a water supply is needed for operation

  • f.a type of latrine that separates urine and faeces

  • g.a type of latrine where the user has to move the excreta along using water

  • h.a modification of the simple pit latrine where the problems of odour and flies have been addressed

The correct answers are:
  • 1 = f
  • 2 = c
  • 3 = a
  • 4 = e
  • 5 = d
  • 6 = h
  • 7 = b
  • 8 = g

SAQ 5.2 (tests Learning Outcome 5.2)

Ato Aschalew, a resident in the outskirts of your town, consults you about building a latrine in the compound of his house. He is an open-minded man who is keen to improve life for his family. He has a wife and three young children, and his elderly mother also lives with them. He doesn’t have a tap in his house and gets water from a nearby well. The area has heavy soil and the rock below is impermeable.

  • a.Which types of latrine are possible choices for him?
  • b.Which types of latrine would you recommend, and why?
  • c.What other advice would you give him about the location, design and construction of the latrine?



    • a.Since he doesn’t have a piped supply of water, Aschalew cannot install a water carriage system; instead, he has to install a dry latrine system. The possible choices are a ventilated improved pit latrine, an Arborloo, a urine-diverting latrine or a biogas latrine.
    • b.The ventilated improved pit latrine would be suitable, but if he has space and farms near him (since he is at the outskirts of town) a composting system is recommended, such as the Arborloo or urine-diverting latrine. This would produce a useful organic compost and so protect the environment. In the urine-diverting latrine, a fertiliser from urine is also produced. Aschalew could sell these products to the farmers. The biogas latrine is not recommended because it is suitable only where there are a large number of users.
    • c.The pit must be at least 30 m away from his well, and it must also be at a lower level according to the slope of the land. He should also consider the wind direction and place the latrine downwind and at a convenient distance from the house. For the safety of the children, he should choose a SanPlat for the slab. He should seek advice about possible materials to be used for the superstructure. The materials should be available locally, so that the system is sustainable. He should install a handwashing facility next to the latrine.

SAQ 5.3 (tests Learning Outcome 5.3)

Galawdeyos and his family comprise a total of seven people. They plan to build a new VIP latrine with a pit with a diameter of 1 m in their back yard. Calculate the depth of pit required if they intend that it should last them three years. Take the sludge accumulation rate to be 40 litres per person per year.


Depth of pit reverse solidus equals cap p multiplication cap s multiplication cap n divided by cap a reverse solidus plus 0.5 times m

P = 7

S = 40 litres per person per year = 0.04 m3 per person per year

N = 3 years

A is pi multiplication d squared divided by four or 3.142 multiplication one squared divided by four equation left hand side equals right hand side 0.79 times m squared

depth = equation left hand side seven multiplication 0.04 multiplication three divided by 0.79 plus 0.5 equals right hand side 1.6 times m

SAQ 5.4 (tests Learning Outcome 5.4)

Which of the following statements are false? In each case explain why it is incorrect.

  • A.For sustainability, it is best to use locally-available materials and skills when constructing latrines.
  • B.The aim should always be to have water-borne toilets such as the WC.
  • C.Constructing a pit latrine with a mound ensures that any water drains away.
  • D.The raised footrests in a latrine help in the proper use of the facility in darkness.
  • E.The cost of the latrine to the user is immaterial, since good health from proper sanitation is priceless.


B is false. Water-flushed toilet systems should only be considered if a continuous supply of water is available.

E is false. Latrines need to be affordable for people to adopt them.

Summary of Study Session 5