NCC 2019 Volume Three
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Part B6 Rainwater harvesting and use
This Part sets out the requirements for the design, construction, installation, replacement, repair, alteration and maintenance of any part of a rainwater harvesting system.
This Part only applies to a rainwater harvesting system that serves a—
This Part does not apply to a rainwater harvesting system that—
OBJECTIVE
BO6
The Objective of this Part is to—
FUNCTIONAL STATEMENTS
BF6
Rainwater harvesting systems must be designed and installed so as to operate in a way that avoids the likelihood of inadvertent contamination of any drinking water service, and minimises any adverse impact on building occupants, the Network Utility Operator's infrastructure, property and the environment.
A rainwater harvesting system must be designed, constructed and installed in such a manner as to reduce the likelihood of stored rainwater becoming contaminated or otherwise posing a hazard to public health.
A rainwater harvesting system must be designed, constructed and installed in such a manner as to—
avoid the likelihood of contamination of water within the rainwater harvesting system, the water service, or the Network Utility Operator's drinking water supply (if connected); and
provide water to fixtures and appliances at flow rates and pressures which are required for the correct functioning of those fixtures and appliances under normal conditions; and
avoid the likelihood of failure and uncontrolled discharge; and
facilitate the efficient use of drinking water; and
allow access, as required, for maintenance of mechanical components and operational controls; and
allow the system, appliances and backflow prevention devices to be isolated for testing and maintenance, where required.
A rainwater service must not have an unprotected cross-connection with any Network Utility Operator's drinking water service or with any non-drinking water service.
Pipes, pipe outlets, storage and holding tanks that form part of a rainwater harvesting system must be clearly identified.
BP6.4 does not apply if the rainwater harvesting system is the only water supply connected to the site.
There are no Verification Methods in this Part.
Performance RequirementsBP6.1 to BP6.4 are satisfied by complying with B6.2 to B6.5.
A rainwater harvesting system must only collect roof water.
Any top-up line from a Network Utility Operator's drinking water supply to a rainwater tank must comply with Part B1.
For the purposes of Section 16 of AS/NZS 3500.1, the following applies:
A rainwater tank that is set into and completely covered by earth is a 'buried tank'.
A rainwater tank that is not in any way set into the ground is an 'above-ground tank'.
A rainwater tank not matching the description at B6.4(1)(a) or B6.4(1)(b) is a 'partially buried tank'.
In determining the appropriate description applicable under this clause, access openings, inlets and outlets to a tank may be ignored.
Rainwater pipework and outlets must comply with Section 16 of AS/NZS 3500.1.
Identification of rainwater pipework and outlets in accordance with clause 16.3.2 of AS/NZS 3500.1 is not required if the rainwater harvesting system is the only water supply available on the site.