Self-Assessment Questions (SAQs) for Study Session 19

Now that you have completed this study session, you can assess how well you have achieved its Learning Outcomes by answering these questions. Write your answers in your Study Diary and discuss them with your Tutor at the next Study Support Meeting. You can check your answers with the Notes on the Self-Assessment Questions at the end of this Module.

SAQ 19.1 (tests Learning Outcomes 19.1, 19.2 and 19.3)

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

A  The decomposition of human waste in a septic tank is an aerobic process.

B  A seepage pit is a watertight underground pit for containing liquid waste.

C  Anaerobic digestion is a method of waste treatment that converts waste into useful products.

D  Runoff does not cause environmental problems because it is only rainwater that runs off the land surface.

E  Protection of groundwater from contamination is an essential requirement of human waste management.


A is false. Decomposition in a septic tank is an anaerobic, not aerobic, process.

B is false. A seepage pit must not be watertight. Liquid must be able to seep slowly out of the pit into the surrounding ground.

C is true. Anaerobic digestion of waste produces biogas and digested sludge that can be used as a fertiliser.

D is false. Runoff is rainwater running off the land but it may contain human and other types of waste that have been washed off the land surface. It can also cause flooding problems.

E is true. Human waste management must ensure the protection of groundwater from contamination.

SAQ 19.2 (tests Learning Outcome 19.4)

Explain why the following factors are important when choosing a sanitation technology.

  • a.local geology
  • b.local climate
  • c.the age range of people using the facilities.


  • a.Local geology is important because the type of rock will need to be considered for any technology that relies on liquid waste percolating into the ground. For example, a pit latrine must be sited further away from a water source if the rock is permeable.
  • b.Climate can make a difference if the usual rainfall pattern causes frequent flooding. This will need to taken into consideration when locating and building the chosen latrine.
  • c.The sanitation technology must be comfortable and convenient for all the people who are going to use it. Small children may need special arrangements that allow them to use the latrine without danger. Elderly people may not be fully mobile and may also need special consideration to ensure the latrine is accessible for them.

Summary of Study Session 19