QUESTION 2
The drawing opposite shows an as-built plan of a foul water drainage system.
The drain is a 110mm uPVC, laid to a gradient of 1.65% (1:60), and has a minimum cover of 500mm.
The drainage system complies with AS/NZS 3500 Part 2: Sanitary plumbing and drainage.
(a)   In the table below, compile a list of all pipe work, inspections, junctions, bends and gullies
required to meet the minimum requirements of AS/NZS 3500 Part 2: Sanitary plumbing and
drainage. Do not include inspections or fittings at the boundary sewer connection, or bends
rising up from the drain to sanitary fixtures or ventilation.   
(b)   Using the costs per item given, calculate the total cost of materials, including allowance for
profit margin and GST.

(5 marks)
(c)  The main drain length is 65.000m. Calculate the depth of the drain invert at the boundary
sewer connection. Show all working. using formula fall = lenght / gradient
                 F= 65 / 60
                       65 *1000mm/p/m =65000mm
                               65000/60= 1083.33 m of fall over 65 m
                              also adding on minimum cover and pipe dia
                               500mm + 100 = 600mm
                               1.083+600 = 1683m to invert