Backflow Prevention Central Coast —
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Backflow occurs when water flows in reverse through your plumbing, allowing contaminated water to enter the clean drinking supply. It can carry chemicals, bacteria, fertilisers, and waste into your taps — and potentially into the wider mains network.

• Backsiphonage — caused by negative pressure from water main breaks or heavy demand, creating a vacuum that sucks contaminated water backward
• Backpressure — when downstream pressure from boilers, pumps, or elevated tanks exceeds supply pressure, forcing water to reverse
• Cross-connections — any point where mains water connects to a potential contamination source (garden hoses, irrigation, pools, rainwater tanks)

The device you need depends on the hazard level of your cross-connection, as defined by AS/NZS 3500:

• RPZ valve (Reduced Pressure Zone) — for high hazard applications like commercial kitchens, swimming pools, and medical facilities. Two check valves plus a relief valve that dumps water rather than allowing contamination
• Double check valve (DCVA) — for medium hazard connections like irrigation systems and standard commercial properties. Two independent spring-loaded check valves
• Non-testable dual check — for low hazard properties, typically built into water meters 25mm and smaller. No annual testing required

Prices vary by device type, brand, and accessibility. Annual testing includes the compliance report submitted to Central Coast Council.

Managing commercial or strata properties on the Central Coast? Annual backflow testing is a legal requirement — the property owner is liable even when a tenant or body corporate manages day-to-day operations. Set up a yearly testing schedule with an accredited plumber to avoid compliance notices and potential fines from Central Coast Council.