CHEMICAL DISPENSERS

One of the most common questions posed to the Backflow Prevention Association of Australia (BPAA) is with appliances that have WaterMark approval as a low hazard and still require a high or medium hazard backflow preventor installed upstream.

Unfortunately, the plumbing laws, standards, and codes do not discriminate between manufacturers or products but are universal and apply to all. Litigation is just one of the issues with appliances having to mix chemicals with the drinking water supply but of more importance to the community is the potential to contaminate the water supply and the impact on humans and the community from the contamination whether in the short or long term. Whilst most appliances must obtain WaterMark approval, this does not allow appliances to be installed without further protection to comply with the deemed to satisfy provisions of the Plumbing Code of Australia (PCA). The installation of chemical proportioning dispensers, dishwashers, and glass washers are one of the most common appliances questioned regarding the correct backflow protection.

For example, these types of appliances require WaterMark Certification to WaterMark Technical Standard (WMTS) WMTS-101:2021 Appliances (low hazard rating), this WMTS sets out minimum product requirements for the connection of appliances to the water service, the WMTS is a WaterMark Scheme and not an installation compliance scheme.

Section 8.2 of this WMTS-101:2021

8.2 Backflow prevention Appliances shall— a. comply with the backflow prevention requirements of IEC 61770; or b. comply with the back siphonage test of AS 2845.2:1996; or c. be supplied with a backflow prevention device complying with AS/NZS 2845.1 and of a type required in AS/NZS 3500.1.

NOTE: 8.2(b) can only be used for testing where the appliance incorporates an air gap or a break tank incorporating an air-gap.

Where backflow prevention devices are required to be installed external to the appliance or apparatus, the devices shall be supplied with the appliance and include appropriate installation instructions.

Once an appliance has been certified by a Certification Assessment Body (CAB), the CAB will need to nominate on the WaterMark Approval how the appliance was assessed as per section 8.2 of the WMTS. This can be found on the Australian Building Codes Board website: watermark.abcb.gov.au.

The BPAA is committed to maintaining a safe drinking water supply through effective management strategies and education which include prevention of contaminants entering the drinking water supply.

Written by Stephen Jennison, Secretary of the Backflow Prevention Association of Australia