NCC 2022 Volume Three - Plumbing Code of Australia
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B1
Part B1 Cold water servicesPart B1 Cold water services
This Part sets out the requirements for any part of a cold water service of a property that is connected to a drinking water supply. It covers from the point of connection to the points of discharge.
This part also applies to a cold water service connected to an alternative water source and residential fire sprinklers installed in accordance with FPAA101D Automatic Fire Sprinkler System Design and Installation - Drinking Water Supply.
Objectives
B1O1
Objective
2019: BO1
The Objective of this Part is to—
Functional Statements
B1F1
Cold water supply
2019: BF1.1
Sanitary fixtures, sanitary appliances and supply outlets providing drinking water must have a safe and adequate piped cold water supply.
B1F2
Cold water service
2019: BF1.2
The cold water service must be conveyed through plumbing installations in a way that minimises any adverse impact on building occupants, the Network Utility Operator’s infrastructure, property and the environment.
B1F3
Fire sprinkler systems
New for 2022
Residential fire sprinkler equipment must be provided with adequate water supply and pressure for its intended purpose.
Performance Requirements
B1P1
Cold water supply
2019: BP1.1
A cold water service must be connected to a drinking water supply.
B1P2
Velocity
2019: BP1.2
Cold water service pipework must ensure that the pipework water velocity does not exceed 3 metres per second for more than 1% of the time that water is required during the annual peak hour.
During the hour of heaviest usage expected to occur in a year, cold water service velocity of 3 metres per second must not be exceeded for 99% of the time downstream fixtures are in use.
B1P3
Access and isolation
2019: BP1.2
B1P4
Water efficiency
2019: BP1.2
A cold water service must ensure the efficient use of drinking water by—
The flush volumes of B1P4 may be within a tolerance of—
The requirements of B1P4 do not apply to a vacuum drainage system.
B1P5
Pressure
2019: BP1.2
The points of discharge for a cold water service must—
B1P5(a)(i) and B1P5(a)(ii) do not apply to existing low-pressure gravity only water services.
Pressure
The points of discharge for a cold water service must—
B1P6
Uncontrolled discharge
2019: BP1.2
A cold water service must avoid failure or uncontrolled discharge.
Deemed-to-Satisfy Provisions
B1D1
Deemed-to-Satisfy Provisions
2019: B1.1
B1D2
Water efficiency
2019: B1.2
For all other installations, cisterns or flushing devices for water closets must—
Prior to installing a programmed solenoid operated flushing system, further advice should be sought from the authority having jurisdiction.
Where sensor control is used for urinal flushing, sensors should be located to avoid unnecessary ‘nuisance’ flushing triggered by pedestrian traffic.
AS/NZS 6400 Water Efficient Products - Rating and labelling, provides the basis for the rating and labelling of a range of products under the mandatory Water Efficiency Labelling and Standards (WELS) Scheme.
B1D2 outlines the minimum level of water efficiency for certain plumbing products and fixtures, however the adoption of products and technologies of greater efficiency should be considered.
B1D3
General requirements
2019: B1.4
General requirements
B1D3(1) does not apply to existing low-pressure gravity only water supply systems.
General requirements
A cold water service must be in accordance with AS/NZS 3500.1, with the following additions to clause 5.4.2: (l) Where valves are located below ground within the property boundary, they shall be provided with a surface box and riser. The box lid shall be permanently marked with a “W”.
General requirements
A cold water service must be in accordance with AS/NZS 3500.1.
B1D4
Bushfire prone areas
New for 2022
A cold water service in a designated bushfire prone area must be in accordance with AS 3959.
B1D5
Cold water fire sprinkler systems
2019:B4.2
A cold water service used for fire-fighting must be in accordance with—
B1D5(b) does not apply to a residential care building.
For all other fire-fighting water services, see Part B4.
B1D6
Top-up lines
2019: B6.3
A cold water service used to top up a rainwater tank must be in accordance with AS/NZS 3500.1.
Installation of cold-water storage tanks used to supply water to a drinking water service must comply with B1D7.
For connection of cold water tanks where reticulated supply is available refer to Sections 8 and 15 of AS/NZS 3500.1.
Information on some of the above items listed in the materials above may be obtainable from the manufacturer or supplier of the product or materials.
Rainwater for drinking purposes should not be collected from recently painted roofs (until after the first few rainfalls), timber roofs preserved with chemicals, roofs coated with lead flashings, lead-based paints or tar-based coatings, or parts of roofs near flues from solid fuel heaters. Rainwater for drinking water purposes may be collected from roof types other than those identified above provided the roof and associated gutters are kept clean of leaves, animal remains, dust and other debris. Gutters must be kept clean by installing screens or leaf diverters between the roof and the water tank. The system should incorporate a ‘first flush system’ or other diversion system that will prevent the first flush of water from entering the tank.
Tanks should be regularly maintained by cleaning out accumulated sludge from the base every 2 - 3 years. For detailed advice on desludging and maintaining tanks refer to the enHealth Guide – Guidance on the use of rainwater tanks; or HB 230 Rainwater tank design and installation handbook
For ongoing maintenance of water quality one or more of the following water quality treatment methods should be adopted: Chlorinating: To commission the tank sufficient chlorine should be added to provide a free chlorine residual of 0.5 mg/L after 30 minutes. To satisfy chlorinating requirements an initial dose of 5 mg/L of chlorine may be necessary. For every kL of water in the tank, add either: 40 mL of liquid pol chlorine (sodium hypochlorite - 12.5% available chlorine); or 8 grams of granular pool chlorine (calcium hypochlorite - 65% available chlorine). To calculate the tank volume in kL for a cylindrical tank the volume in of water in kL = D x D x H x 0.785. Where D = diameter of the tank, and H = depth of water in the tank in metres. To verify this calculation, compare this volume with the maximum capacity of the tank. The chlorine residual may be tested with a swimming pool test kit or dip strips. Water after chlorinating should not be used for 24 hours to enable any harmful microorganisms to be killed off. Filtration: If filters are used in drinking water installations they are to be certified to the relevant Australian Standard under the WaterMark Certification Scheme and should be maintained by following the manufacturer’s maintenance instructions. Ultraviolet Disinfection: Filtration may be required to address water turbidity to enable adequate UV disinfection. Ultraviolet treatment is affected by the levels of turbidity, organic content from suspended solids, pH, hardness and UV transmissivity of the water. The intensity of the UV light and the build-up of suspended solids on the quartz tube affect the disinfection performance. Regular monitoring of the quartz tubes is critical. Lamps also need to be replaced regularly in accordance with the manufacturer’s instructions.
Cold water storage tanks
NCC Volumes One and Two deal with a number of areas of on-site construction which are relevant to cold water services. These include, but may not be limited to, those listed in Table B1.
Item | NCC Volume One Class 2 to 9 buildings | NCC Volume Two Class 1 and 10 buildings |
---|---|---|
Excavations for pipework adjacent to a building and footings | B1 Structural provisions | H1 Structure |
Termite management for attachments to buildings and penetrations through a slab | B1 Structural provisions | H1 Structure |
Penetrations for pipework through a vapour barrier | B1 Structural provisions | H1 Structure |
Pipework in timber bearers and joists of solid timber or engineered wood products | B1 Structural provisions | H1 Structure |
Fittings, fixtures and pipework installations in steel framed construction | B1 Structural provisions | H1 Structure |
Penetrations through a fire-resisting wall or floor | C1 Fire resistance Performance Requirements and C4 Protection of openings | H3 Fire safety |
Fixtures and fittings in a wet area | F2 Wet areas and overflow protection | H4 Health and amenity |
Service pipework external to the building and penetrations through roof cladding in a bushfire prone area | G5 Construction in bushfire prone areas | H7 Ancillary provisions and additional construction requirements |
Pipework sound insulation | F7 Sound transmission and insulation | H4 Health and amenity |
Flues, chimneys, pipes, gas storage, domestic fuel tanks, cooling or heating appliances or other services | C4 Protection of openings | H3 Fire safety |
Power supply to boiling and/or chilled water storage units | J7 Artificial lighting and power | Not applicable |