NCC 2022 Volume Three - Plumbing Code of Australia


Part C2 Sanitary drainage systems

Part C2 Sanitary drainage systems

NSW C2D4 General requirements2019: NSW C2.4

Delete clause C2D4 and insert NSW C2D4 as follows:

A sanitary drainage system must be in accordance with AS/NZS 3500.2 with the following variations:

  1. For clause 4.3.1 insert (i) as follows: Must not have DN40 or DN50 traps installed.
  2. For clause 4.4.1 insert the following as the second paragraph: Boundary trap or inspection shafts cannot terminate within areas of buildings as defined in the NCC as a habitable room. See NCC “Definitions” and delete ‘but’ from (a) and replace with ‘,” and delete ‘excludes’ from (b).
  3. After clause 4.5.2(b) insert (c) as follows: Soil and waste stacks shall not discharge through a reflux valve except where a reflux valve is installed at the connection to the sewer required with surcharging sewers.
  4. Substitute clause 4.5.3 as follows: Where a surcharge is likely to occur and a reflux valve is to be installed, it shall be located in accordance with (i) and (ii) as follows:
    1. Where the drain has an inspection shaft or boundary trap, the reflux valve shall be located immediately downstream from and adjacent to the outlet of the shaft or trap.
    2. The invert of the outlet of the reflux valve shall be installed a minimum of 80 mm higher than the invert of the Network Utility Operator’s system it is connected to. See NSW Figures C2D4a and C2D4b.
  5. After clause 4.7.1(h) insert (i) as follows: At each branch off a main line internal of the building connecting one or more water closets or slop hoppers. In these cases. inspection openings must be raised to finished surface level in an accessible position and sealed with an airtight cover. If access to the under floor area is more than 600 mm above the inspection opening, the riser may be omitted.
  6. After clause 12.7(g) insert (h) as follows: Sewage management facilities shall be accredited by NSW Health and comply with local government requirements. Before a connection is made to pump raw sewage or effluent from a septic tank or holding well to the Network Utility Operator’s sewer, an application must be made to that Network Utility Operator. Applicants must meet the pump to sewer requirements and conditions for all connections to the sewer. A marker tape must be laid along the top of all pump discharge or rising mains pipes at intervals of not more than 3 m.
Insert NSW figure (C2D4a) C2D4 as follows:
NSW Figure C2D4a: Reflux valves - diagram 1
Insert NSW figure (C2D4b) C2D4 as follows:
NSW Figure C2D4b: Reflux valves - diagram 2


Where a reflux valve is installed the valve remains the responsibility of the property owner.