TAS Part C4 On-site liquid trade waste systems

An on-site liquid trade waste system must ensure—

1. the risks associated with the discharge of treated liquid trade waste to the environment are minimised; and
2. surface water and ground water are not polluted; and
3. soil productivity is maintained or enhanced.

(1) Liquid trade waste must be transferred within the disposal system and treatment devices in a way that avoids—

1. blockage and uncontrolled discharge: and
2. the entry of foul air and gasses into buildings.

(2) Liquid trade waste must be transferred within the disposal system and treatment devices in a way that ensures—

1. the safe and hygienic transferal of waste; and
2. safe access for clearing blockages.

(1) A trade waste treatment device must—

1. have appropriate treatment and storage capacity for the volume of waste and frequency of disposal: and
2. be of the appropriate size, strength and rigidity for the nature, flowrates, volume of wastes, by-products and residues which must be processed; and
3. have vehicle access for collection of waste, where appropriate; and
4. be of an appropriate structural strength for when pedestrian or vehicular traffic is likely; and
5. be constructed from materials which are resistant to water and the expected waste that will be disposed.

(2) A trade waste treatment device must avoid the likelihood of—

1. contamination of drinking water, soils, ground water and waterways; and
2. foul air and gasses accumulating within or entering buildings; and
3. uncontrolled discharge; and
4. the unauthorised access by people; and
5. the entry of stormwater to the sewerage system.

(3) A trade waste treatment device must allow for—

1. cleaning, maintenance, measurement and performance sampling provisions to the requirements of the Authority having jurisdiction; and
2. the identification of the manufacturer, model, serial number and capacity after installation.

(4) A trade waste treatment device must continue to satisfy the requirements of C4P1- C4P3 throughout its expected lifetime.

(5) A trade waste treatment device must be approved by—

1. the receiving Network Utility Operator; or
2. The Authority having jurisdiction for on-site wastewater management systems.

Performance Requirements C4P1 to C4P3 are satisfied by complying with C4D2 to C4D19.

(1) Where pre-treatment facilities are installed, they must comply with the requirements of—

1. the Network Utility Operator (where applicable); and
2. occupational health and safety; and
3. dangerous goods management; and
4. environmental protection.

(2) A liquid trade waste system that discharges to a Network Utility Operator's sewerage system after pre-treatment must—

1. be capable of discharging liquid trade waste at a quality set under a Consent to Discharge issued for that equipment or system by the Network Utility Operator; and
2. the sanitary drainage system must comply with:
   1. AS/NZS 3500.2; and
   2. the Network Utility Operator's guidelines, insofar as the provisions relate to the system.

(1) Low-risk trade waste appliances must be located as close as practicable to the fixtures served, whether installed internally or externally and may be above or below ground.

(2) Portable appliances must only be installed above ground.

Trade waste appliances must be fitted with covers which can withstand vehicular or pedestrian traffic or other loads likely to be imposed on them and be easily removable by one person.

Trade waste appliances must be constructed from materials suitable for the characteristics of the liquid wastes likely to be discharged.

(1) Where airtight covers are fitted, trade waste appliances must be vented with a minimum DN 50 vent.

(2) Outlet ventilation is to be provided by either a—

1. DN 100 riser from a disconnector gully outside a building; or
2. DN 50 vent from a disconnector gully at the outlet of a non-portable appliance inside a building; or
3. DN 50 vent from a DN 80 trap riser at the outlet of a portable appliance, inside a building.

(3) Trade waste appliance vents and outlet vents may be combined inside a building.

(4) Ventilation must be provided in accordance with AS/NZS 3500.2.

(1) The plumbing and drainage installation upstream of a low-risk trade waste appliance must comply with AS/NZS 3500.2

(2) The sanitary plumbing and drainage system must be compatible to the nature of the waste.

(3) A trap must be fitted to every fixture or appliance outlet and must be—

1. DN 50 minimum for a portable appliance with hydraulic loading up to 5 fixture units; or
2. DN 80 minimum for a portable appliance with hydraulic loading greater than 5 fixture units; or
3. DN 100 minimum for all other appliances.

(1) The silt pit must be connected and authorised by the Permit Authority.

(2) The silt pit bucket must—

1. be constructed of mild steel plate, minimum 3 mm thick with 4 rows of 10 mm diameter holes at 25 mm centres: and
2. be hot dipped galvanised after fabrication.

(1) The silt trap must be connected and authorised by the Permit Authority.

(2) The silt trap bucket must—

1. be constructed of mild steel plate, minimum 3 mm thick with 5 rows of 10 mm diameter holes at 25 mm centres; and
2. be hot dipped galvanised after fabrication.

(1) The straining pit must be connected and authorised by the Permit Authority.

(2) The straining pit basket must—

1. be constructed of mild steel wire with a minimum diameter of 2.5 mm woven to give 7 mm aperture widths on a 32 mm x 32 mm x 25 mm angle iron frame with mitred corners; or
2. be constructed from minimum 3 mm thick mild steel plate, with 6 holes at 12 mm centres over the entire area of the basket; and
3. be hot dipped galvanised after fabrication.

(1) The straining trap must be connected and authorised by the Permit Authority.

(2) The straining pit basket must—

1. be constructed of mild steel wire with a minimum of 2.5 mm woven to give 7 mm aperture widths on a 32 mm x 32 mm x 25 mm angle iron frame with mitred corners with a top frame of welded angle iron; or
2. be constructed from minimum 3 mm thick mild steel plate, with 6 mm holes at 12 mm centres over the entire area of the basket; and
3. be hot dipped galvanised after fabrication.

(3) If the straining trap is to be used in installations connected to the Network Utility Operator's sewerage system, it must comply with the requirements of the Network Utility Operator's guidelines for pre-treatment devices.

(1) A grease interceptor must contain a permanently fixed, ridged baffle constructed of a minimum 6 mm—

1. mild steel plate; or
2. other authorised material.

(2) A grease interceptor must be installed on a minimum of 75 mm compacted packing sand.

(3) A grease interceptor must have a minimum DN 50 vent where airtight covers are fitted.

(4) A grease interceptor installed underground must be constructed with—

1. minimum 100 mm concrete walls with a smooth internal finish; and
2. have suitable reinforcing mesh within the concrete.

(5) A grease interceptor installed above ground must—

1. be constructed of an authorised material; and
2. provide adequate structural support.

(6) The capacity of a grease interceptor must be authorised by the Permit Authority.

(7) A grease interceptor must be installed in a location that will facilitate ready access for maintenance and inspection.

(1) The capacity of a portable grease interceptor must be authorised by the Permit Authority.

(2) A portable grease interceptor must contain a permanently fixed, ridged baffle constructed of a minimum—

1. 6 mm unplasticised polyvinyl chloride (PVC-U); or
2. 0.79 mm galvanised sheet steel; or
3. 0.63 mm copper sheet; or
4. 0.63 mm of 316 stainless steel; or
5. Other authorised material.

(3) A portable grease interceptor must be provided with airtight covers using lever clips.

(4) Ventilation of portable grease interceptors must—

1. be extended to open air; and
2. comply with AS/NZS 3500.2.

(5) A portable grease interceptor must be located in a position that enables ready access for maintenance and inspection.

(6) A portable grease interceptor must be protected from direct sunlight.

(1) Grease trap chambers must provide adequate ventilation by providing—

1. two DN 100 vents in addition to the ventilation provided for the sanitary drainage system; or
2. appropriate mechanical ventilation.

(2) Anti-siphon vents must be—

1. a minimum of DN 50: and
2. connected to the outlet of the grease trap chamber.

Grease traps in multi-storey buildings must have a reflux valve installed between the outlet and connection to the sanitary plumbing system.

(1) The capacity of an oil and petrol interceptor must be authorised by the Permit Authority.

(2) An oil and petrol interceptor must contain a permanently fixed, ridged baffle constructed of a minimum—

1. 6 mm mild steel plate; or
2. other authorised material.

(3) PVC-U must not be used for the construction, connection or venting of an oil and petrol interceptor.

(4) An oil and petrol interceptor must be provided with airtight covers that are suitable size and be readily removable by one person.

(5) The inlet and outlet of the oil and petrol interceptor pit is to be covered with either a 600 mm x 600 mm or 600 mm diameter cover.

(6) Ventilation of oil and petrol interceptors must—

1. be extended to open air; and
2. comply with AS/NZS 3500.2.

(7) An oil and petrol interceptor must be located in a position that enables ready access for maintenance and inspection.

(8) Outlet fittings from an oil and petrol interceptor must be manufactured from one piece of DN 100 cast iron pipe.

(9) An oil and petrol interceptor must be protected from traffic loads by a suitable cover.

(10) When an oil and petrol interceptor is connected to the Network Utility Operator's sewerage system. it must comply with the requirements of the Network Utility Operator's guidelines for pre-treatment devices.

(1) The capacity of an acid neutralising tank must be authorised by the Permit Authority.

(2) An acid neutralising tank and fixed baffles must be constructed of a minimum—

1. 6 mm PVC-U sheet; or
2. 0.63 mm acid resistant stainless steel all welded construction; or
3. other authorised acid and alkali resistant material.

(3) An acid neutralising tank must contain three equally spaced baffles.

(4) An acid neutralising tank must be manufactured with—

1. the diameter of the outlet pipe being at least one size larger than the inlet pipe (i.e. DN 65 inlet - DN 80 outlet); or
2. where the inlet pipe is DN 100, the diameter of the outlet may be DN 100.

(5) The outlet of an acid neutralising tank must include a 32 mm x 32 mm x 25 mm deep PVC-U test block bracket fitted as near as practicable to the outlet.

(6) An acid neutralising tank must include a 150 mm x 25 mm x 25 mm cement mortar test block fitted to the satisfaction of the Permit Authority.

(7) An acid neutralising tank must include marble chips in the 40 mm to 60 mm size range.

(8) An acid neutralising tank must be located in a position that—

1. enables ready access for maintenance and inspection; and
2. provides ready access for fitting of the cement mortar test block; and
3. enables ready access to the sampling valve; and
4. provides ready access for replacement of the marble chips.

(9) When an acid neutralising tank is to be located below ground level, it must—

1. be surrounded with concrete walls and base with a minimum thickness of 100 mm; and
2. omit the 25 mm sampling valve; and
3. have a minimum DN 100 outlet pipe located no deeper than 600 mm below surface level; and
4. have the outlet pipe connected to a disconnector gully fitted with a loose fitting grate or screwed cap.

(1) The capacity of a mixing tank must be authorised by the Permit Authority.

(2) A mixing tank and baffles must be constructed of a minimum—

1. 6 mm PVC-U sheet; or
2. 0.63 mm acid resistant stainless steel all welded construction; or
3. other authorised acid and alkali resistant material.

(3) A mixing tank must contain three equally spaced baffles.

(4) A mixing tank pipe diameter must be—

1. DN 100 when the pipe inlet size is DN 100; or
2. a minimum of one size larger than the inlet pipe.

(5) The outlet of a mixing tank must include a 32 mm x 32 mm x 25 mm deep PVC-U test block bracket fitted as near as practicable to the outlet.

(6) A mixing tank must include a 150 mm x 25 mm x 25 mm cement mortar test block fitted to the satisfaction of the Permit Authority.

(7) A mixing tank must be located in a position that—

1. enables ready access for maintenance and inspection; and
2. provides ready access for fitting of the cement mortar test block; and
3. enables ready access to the sampling valve.

(8) When a mixing tank is to be located below ground, it must—

1. be surrounded with concrete walls and base with a minimum thickness of 100 mm; and
2. omit the 25 mm sampling valve; and
3. have a minimum DN 100 outlet pipe located no deeper than 600 mm below surface level; and
4. have the outlet pipe connected to a disconnector gully fitted with a loose fitting grate or screw cap.

(1) The capacity of a settling tank must be authorised by the Permit Authority.

(2) The settling tank and baffles are to be constructed of a minimum—

1. 6 mm unplasticised polyvinyl chloride (PVC-U); or
2. 0.79 mm galvanised sheet steel; or
3. 0.63 mm copper sheet; or
4. 0.63 mm 316 stainless steel; or
5. other authorised acid and alkali resistant material.

(3) The diameter of the outlet pipe must be—

1. DN 100 when the outlet size is DN 100; or
2. a minimum one size larger than the inlet pipe.

(4) A settling tank must be located in a position that enables ready access for maintenance, sampling and inspection.

(5) Where a settling tank is to be located below ground level, it must—

1. be surrounded with concrete walls and base with a minimum thickness of 100 mm; and
2. omit the 25 mm sampling valve; and
3. have a minimum DN 100 outlet pipe located no deeper than 600 mm below surface level; and
4. have the outlet pipe connected to a disconnector gully fitted with a loos fitting grate or screwed cap.