NCC 2022 Volume Three - Plumbing Code of Australia

B1

Part B1 Cold water services

Part B1 Cold water services

Introduction to this Part

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

The Objective of this Part is to—

  1. safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a cold water installation; and
  2. ensure that a cold water installation is suitable; and
  3. conserve water and energy; and
  4. safeguard the environment; and
  5. safeguard public and private infrastructure; and
  6. ensure that a cold water installation is designed and is capable of being maintained so that throughout its serviceable life it will continue to satisfy Objectives (a) to (e).

Functional Statements

Sanitary fixtures, sanitary appliances and supply outlets providing drinking water must have a safe and adequate piped cold water supply.

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.

Residential fire sprinkler equipment must be provided with adequate water supply and pressure for its intended purpose.

Performance Requirements

A cold water service must be connected to a drinking water supply.

Applications

  1. B1P1 applies to cold water supplied for human consumption, food preparation, food utensil washing or personal hygiene.
  2. B1P1 applies to automatic fire sprinkler systems when installed in accordance with FPAA101D Automatic Fire Sprinkler System Design and Installation - Drinking Water Supply.

Explanatory information: Unintentional heating of cold water services

  • Where installed in a location subjected to extreme summer temperatures (such as the roof space of a building), cold water services have the potential to become unintentionally heated. This can pose a hazard as the cold water supply may reach temperatures in excess of 45° Celsius, increasing the potential for scalding.
  • To reduce the likelihood of unintentional heating of cold water services, consideration should be given to—
    1. avoiding long runs of pipework in locations exposed to solar heat gain; or
    2. applying insulation, either directly to the pipework, or by using additional ceiling insulation material between the pipework and the solar heat source.
  • Avoidance of unintentional heating of cold water services in known areas of extreme summer temperatures may also assist in reducing water usage through drawing off of water which has become excessively heated.

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.

Explanatory information

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.

(1) A cold water service must ensure access for maintenance of mechanical components and operational controls.

(2) A cold water service must ensure the system, appliances and devices can be isolated for testing and maintenance.

A cold water service must ensure the efficient use of drinking water by—

  1. limiting water usage from—
    1. a tap or outlet for a shower, basin, kitchen sink or laundry trough, to a flow rate of not more than 9 l/m; and
    2. a cistern or flushing device for a urinal, to a flush volume of not more than 2.5 litres for each—
      1. single urinal stall; or
      2. 600 mm length of a continuous urinal wall; and
    3. a dual flush cistern or flushing valve that is connected to a water closet pan to a flush volume of not more than—
      1. 6 and 3 litres; or
      2. 4.5 and 3 litres; or
  2. water saving measures equivalent to or greater than those described in (a).

Applications

The flush volumes of B1P4 may be within a tolerance of—

  1. ±0.5 litres for the full flush of a 6/3 litre cistern; or
  2. +0.5 litres for the reduced flush of a 6/3 litre cistern; or
  3. ±0.2 litres for a 4.5/3 litre cistern.

Exemptions

The requirements of B1P4 do not apply to a vacuum drainage system.

NCC Blurbs

The points of discharge for a cold water service must—

  1. have—
    1. a working pressure of not less than 50 kPa; and
    2. a static pressure within the building of not more than 500 kPa; or
  2. have water pressures suitable for the correct functioning of the fixture or appliance where water pressures outside of (a)(i) and (a)(ii) are required.

Exemptions

B1P5(a)(i) and B1P5(a)(ii) do not apply to existing low-pressure gravity only water services.

NCC Title

Pressure

NCC State
TAS
NCC Variation Type
Replacement
NCC SPTC Current
Pressure

The points of discharge for a cold water service must—

  1. have—
    1. a working pressure of not less than 50 kPa; and
    2. a static pressure within the building of not more than 500 kPa; or
  2. have water pressures suitable for the correct functioning of the fixture or appliance where water pressures outside of (a)(i) and (a)(ii) are required.

A cold water service must avoid failure or uncontrolled discharge.

Deemed-to-Satisfy Provisions

(1) Performance RequirementB1P1 is satisfied if the cold water service is connected to—

  1. the Network Utility Operator’s drinking water supply; or
  2. an alternative drinking water supply.

(2) Where a Deemed-to-Satisfy Solution is proposed, Performance Requirements B1P2 to B1P6 are satisfied by complying with B1D2 to B1D6.

(3) Where a Performance Solution is proposed, the relevant Performance Requirements must be determined in accordance with A2G2(3) and A2G4(3) as applicable.

(1) A tap or outlet used for a shower, basin, kitchen sink or laundry trough must be a minimum of 3 Star WELS rated and discharge not more than 9 litres per minute.

(2) Cisterns or flushing devices for water closets must—

  1. have a dual flushing mechanism; and
  2. be a minimum 3 Star WELS rating discharging not more than 6 litres or 4.5 litres for a full flush.

QLD B1D2 Water efficiency2019: B1.2

Delete subclause B1D2(2) and insert B1D2(2) as follows:

(2) For a new Class 1 or Class 2 building, in an area serviced by a Network Utility Operator water supply, toilet cisterns must—

  1. have a dual flushing mechanism; and
  2. be a minimum 4 Star WELS rating discharging not more than 4.5 litres for a full flush; and
  3. are compatible with the size of the toilet bowl to allow for proper functioning of the toilet.

For all other installations, cisterns or flushing devices for water closets must—

  1. have a dual flushing mechanism; and
  2. be a minimum 3 Star WELS rating discharging not more than 6 litres or 4.5 litres for a full flush.

(3) Cisterns or flushing devices for urinals must—

  1. be a minimum 2 Star WELS rating discharging a volume of not more than 2.5 litres for each—
    1. single urinal stall; or
    2. 600 mm length of continuous urinal wall; and
  2. not be set-cycled or activated by any method other than manual or use activation.

Applications

  1. B1D2(1) applies to outlets that provide cold water only. The Deemed-to-Satisfy Provision for outlets that deliver a combination of cold water and heated water is B2D4.
  2. The flush volumes of B1D2(2) and B1D2(3) may be within a tolerance of—
    1. ±0.5 litres for the full flush of a 6/3 litre cistern; or
    2. +0.5 litres for the reduced flush of a 6/3 litre cistern; or
    3. ±0.2 litres for a 4.5/3 litre cistern.

Exemptions

  1. The requirements of B1D2(1) do not apply to a shower intended to provide rapid drenching of a person for emergency purposes, such as chemical removal.
  2. The requirements of B1D2(2) and B1D2(3) do not apply to a vacuum drainage system.
  3. The requirements of B1D2(3)(b) do not apply to a programmed solenoid operated flushing system if programmed to shut down during extended periods of non-occupancy of a building.

Explanatory information

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.

NCC Blurbs

(1) A cold water service must be in accordance with AS/NZS 3500.1.

(2) Drinking water that is not intentionally heated must be delivered at a temperature of less than 40°C.

(3) A hose tap must be provided in men's public toilets adjacent to the urinals.

NCC Title

General requirements

NCC State
VIC
NCC Variation Type
Replacement
NCC SPTC Current
General requirements
NCC Blurbs

(1) The design, construction, installation, repair, alteration, additions, maintenance and commissioning of cold water services must be in accordance with AS/NZS 3500.1.

(2) Cold water tanks forming part of a drinking water supply must comply with TAS B1D7.

(3) Backflow prevention for boundary containment must comply with the Network Utility Operator Boundary Backflow Containment Selection Requirements.

Exemptions

B1D3(1) does not apply to existing low-pressure gravity only water supply systems.

NCC Title

General requirements

NCC State
TAS
NCC Variation Type
Replacement
NCC SPTC Current
General requirements
NCC Blurbs

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”.

NCC Title

General requirements

NCC State
NSW
NCC Variation Type
Replacement
NCC SPTC Current
General requirements

A cold water service must be in accordance with AS/NZS 3500.1.

A cold water service in a designated bushfire prone area must be in accordance with AS 3959.

A cold water service used for fire-fighting must be in accordance with—

  1. the requirements of E1 of Volume One, where applicable; and
  2. FPAA 101D when installed in a Class 2 or Class 3 building with an effective height of not more than 25 m and a rise in storeys of 4; and
  3. AS/NZS 3500.1.

Exemptions

B1D5(b) does not apply to a residential care building.

Explanatory information

For all other fire-fighting water services, see Part B4.

A cold water service used to top up a rainwater tank must be in accordance with AS/NZS 3500.1.

NCC Blurbs

(1) B1D7 applies to tanks — including rainwater tanks — connected to the roof plumbing system, or a tank supplied from a nearby stream, bore or well used in drinking water services, or a drinking water supply in reticulated or non-reticulated areas.

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.

(2) Cold water storage tanks and their installation must comply with the relevant requirements of the following documents—

  1. AS 2070 Plastics materials for food contact use
  2. AS 3600 Concrete structures
  3. AS 3735 Concrete structures retaining liquids
  4. AS/NZS 2179.1 Specifications for rainwater goods, accessories and fasteners – Metal shape or sheet rainwater goods, and metal accessories and fasteners
  5. AS/NZS 3500.0 Plumbing and drainage
  6. AS/NZS 3500.1 Water services
  7. AS/NZ 3500.3 Stormwater drainage
  8. AS/NZS 4020 Testing of products in contact with drinking water
  9. AS/NZS 4130 Polyethylene (PE) pipes for pressure applications
  10. AS/NZS 4766 Polyethylene storage tanks for water and chemicals
  11. ABCB Procedures for the Certification of Plumbing and Drainage Products Section B Water services Tasmania
  12. NCC 2019 Volume Three - Plumbing Code of Australia Page 134
    1. The followings references are for information only— HB 230 Rainwater Tank Design and Installation Handbook and the enHealth Guidance on the use of rainwater tanks

(3) Materials and products in contact with water in a drinking water supply must comply with AS/NZS 4020. Linings and coatings must comply with AS/NZS 4020 at a surface area to volume ratio not greater than that specified in the conditions of use. Materials and products used in manufacture of tanks must be selected to ensure fitness for their intended purpose. Tanks must be selected from the relevant Standards listed in this Part. Factors to be taken into account include — but are not limited to—

  1. the nature and source of the water;
  2. the risk of corrosion and tank contamination;
  3. the nature of the environment;
  4. the physical and chemical characteristics of the materials and products;
  5. compatibility of materials and products; and
  6. accessibility for monitoring and maintenance.

(4) Plastic tanks must comply with AS/NZS 4766

(5) Waterstops, joint fillers and sealants used in the manufacture of tanks must be certified under the WaterMark Certification Scheme to AS/NZS 4020.

(6) Solders used in the manufacture of tanks must be certified under the WaterMark Certification Scheme to AS/NZS 4020. Soft solder must comply with AS 1834.1 and be lead-free for roof drainage components used for the conveyance of drinking water.

(7) Stainless steel sheet must be manufactured from alloy 304 or 316 complying with ASTM A240/A240M.

(8) Dezincification resistant (DR) copper alloys Where dezincification resistant copper alloys are specified, they must comply with AS 2345.

(9) Steel sheet Hot-dipped zinc-coated or aluminium/zinc-coated sheet steel must comply with AS 1397 and have an internal lining or coating certified to AS/NZS 4020.

(10) Concrete tanks must comply with AS 3735 or AS 3600.

(11) Tank linings must comply with AS/NZS 4020.

(12) In addition to the marking requirements set out in clause 8.9 of AS/NZS 3500.1 all tanks must be permanently marked with the following—

  1. Manufacturer’s name, brand or trademark, and
  2. The Standard which the tank is manufactured to, and
  3. The date of manufacture.

(13) A sludge valve must be fitted when the capacity of the tank exceeds 500 Litres. The minimum size of the valve must be not less than half the outlet pipe size and not less than DN 40.

(14) All openings to tanks must be sealed so that insects, small animals, birds and sunlight cannot enter tanks, in order to minimise the growth of algae and to prevent unauthorised access.

(15) Before using the water from a tank for the first time the tank must be cleaned and disinfected (See Appendix I of AS/NZS 3500.1).

(16) The manufacturer’s warranty must contain the following statement: “This tank has been manufactured for the storage of drinking water and all materials used are suitable for contact with drinking water.”

Explanatory information

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.

NCC Title

Cold water storage tanks

NCC State
TAS
NCC Variation Type
Insertion
NCC SPTC Current
Cold water storage tanks

Explanatory information: Cross-volume considerations

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.

Table B1 Cross-volume considerations
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