QUESTION 4
(a)   Describe a septic tank and state its purpose.
 
 
 
 
 
 
(3 marks)
(b)   Explain what is known as the cascade level in a septic tank.
 
 
(1 mark)
(c)   Explain the purpose of a sullage tank. 
 
 
(1 mark)
(d)  While installing a septic tank at a house under construction, a drainlayer discovers that
the water table is high. State what action the drainlayer should take to ensure that the
installation remains as laid.
 
 
(1 mark)

(e) Define the term absorption test.
 
 
 
(2 marks)
Total 8 marks

Linkback: https://www.plumbers.nz/drainlaying-exam-june-2007/28/question-4/201/