Backflow, Bore Water and a Restaurant Fit-Out
A plumber is fitting out a new 120-seat restaurant in a mixed-use building. The design includes a coffee machine, a carbonated drink system, a commercial dishwasher and a garden tap fed from a bore on the property. The building has a single master meter. The plumber plans to connect the bore supply to the garden tap and also tee it into a hand basin in the staff area 'for washing up'. The council has issued a plumbing approval with conditions requiring backflow protection appropriate to the hazard. The fit-out must open in 10 days for a booked event. The plumber has not yet checked the device register or the hazard ratings of the connected appliances.
1. Identify the backflow risks in this fit-out and explain how the plumber should determine the correct protection for each connection.
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Several connections create backflow hazards. The bore supply is a private, non-potable source and must not be connected to the potable system without appropriate protection; teeing it into a hand basin used for washing is a cross-connection and is not acceptable. The coffee machine, carbonated drink system and commercial dishwasher are mechanical connections that can create backflow risk depending on their hazard rating, and each needs protection selected to match that rating. The plumber should check the council's approval conditions, the applicable plumbing standard and the device register, and confirm the hazard rating of each appliance from the manufacturer's information rather than guessing. Protection might range from a suitable air gap to a testable backflow prevention device, depending on the hazard. The plumber must not connect the bore to the potable system at all for the basin. Any testable device must be commissioned and tested by an appropriately qualified person, and the result recorded.
2. The opening is in 10 days and the plumber is under pressure. What are the plumber's obligations regarding notification, testing and documentation before the restaurant can open?
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The work is regulated plumbing work and is notifiable under the approval; the plumber must complete it in accordance with the approval conditions and arrange the required inspections. Testable backflow prevention devices must be tested on commissioning and the test report provided to the property owner and, where required, the council or water authority. The plumber should record the device type, location, hazard rating and test result, and provide the client with the compliance documentation. The plumber should also confirm that the bore connection is isolated from potable supply and that the hand basin is fed only from potable water. Opening pressure does not justify skipping notification or testing; an untested device or an undocumented cross-connection risks contamination of the building's supply and exposes the plumber to enforcement action. If the 10-day deadline cannot be met compliantly, the plumber should tell the client in writing and agree a revised programme.