Part B5 Cross-connection control
SA B5D6 Rainwater2019: SA B1.4(1) and (2)
Delete clause B5D6 and insert SA B5D6 as follows:
Protection of drinking water services from rainwater must be in accordance with AS/NZS 3500.1(2018) Clause 16.4 and Table 16.4 with the additions;
- After 16.4, insert clause 16.4.1 as follows: 16.4.1 A reduction of the Hazard Rating listed in table 16.4 may be permitted following a risk assessment of the design and installation of the rainwater tank and other environmental factors in accordance with clause 16.4.2.
- After 16.4.1, insert clause 16.4.2 as follows: 16.4.2 For buried rainwater tanks and partially buried rainwater tanks without connection to a drinking water supply or with direct or indirect connections to a drinking water supply, a dual-check valve may be used in lieu of a testable device for Containment protection and Zone protection where it has been determined by risk assessment that—
- the risk to tank rainwater quality from air pollution is low; and
- the risk to tank rainwater quality from groundwater and/or surface water contamination is low. In assessing this risk the permeability of the tank and piping materials and joints to groundwater contaminants should be addressed; and
- precautions in the design and installation of the rainwater collection system have been taken to reduce impacts to tank rainwater quality from the roof collection and delivery system. Such measures include, but are not restricted to, appropriate materials, gutter guards, filters, first flush devices, dry inlets, guards to exclude vermin and mosquitoes, and the quality of tank maintenance programs; and
- precautions in the design and installation of the rainwater tank have been taken to reduce impacts to tank rainwater quality from groundwater and surface water pollution. Such measures include, but are not limited to—
- location and topography; and
- structural integrity of the tank including installation factors such as bedding, embedment, compaction and geotechnical specifications; and
- water tightness of tank including all penetrations, connections, access covers and joints; and
- ingress of vermin through the overflow e.g. by provision of a reflux valve, self-sealing valve, trap check valve; and
- the risk assessment results must be submitted to the authority having jurisdiction.