Plumbing-led Legionella control — hot water temperature management, warm-water system maintenance, dead-leg removal, system flushing and NSW cooling-tower compliance.
Legionella pneumophila is a waterborne bacterium that causes Legionnaires' disease — a severe and sometimes fatal form of pneumonia. It spreads when people inhale fine water droplets contaminated with the bacteria. The bacterium thrives in water between approximately 25°C and 45°C. Below 20°C it is dormant. Above 60°C it is killed.
This temperature relationship is why plumbing is the primary control mechanism — if your hot water is stored at the right temperature and your system has no stagnant sections sitting in the growth range, Legionella cannot colonise.
Hot water must be stored at a minimum of 60°C to suppress Legionella. The solution is a thermostatic mixing valve (TMV), which stores water hot for safety against bacteria and delivers it at a controlled 43.5°C to 45°C for scald protection. This is why Legionella control and TMV testing are inseparable.
Hot and cold water temperature control — verifying storage stays at or above 60°C and that cold water stays cold.
Warm-water-system management — the highest-risk systems, maintained with monitoring, flushing and design review.
Dead-leg identification and removal — eliminating stagnant pipe runs where bacteria breed.
System flushing and recommissioning — flushing low-flow runs and recommissioning systems after treatment or extended vacancy.
TMV and backflow integration — coordinating temperature control with TMV testing and backflow prevention under one plan.
Documentation and reporting — clear records ready for audit.
If your facility operates a cooling tower, it falls under the NSW Legionella Control Regulations (2018). Each system must have a risk management plan, undergo an independent annual audit, be registered with the local authority, complete monthly compliance reports, and undergo monthly laboratory testing — with high results reported within 24 hours.
We coordinate the plumbing-side obligations and work alongside your water-treatment provider.
Legionella control is not a stand-alone task — it is the product of correct temperatures, sound system design, working TMVs, protected supply and disciplined flushing. O'Brien delivers all of those under one licensed contractor and one commercial maintenance plan. One partner, one schedule, one set of records.
Legionella is suppressed when hot water is stored at a minimum of 60°C. Water between roughly 25°C and 45°C is the danger zone.
A dead leg is a section of pipe where water sits still. Stagnant water in the growth-temperature range is an ideal breeding site.
Yes. They carry the highest potential for systemic Legionella colonisation.
Risk management plan, independent annual audit, registration, monthly compliance reporting, and monthly laboratory testing.
Yes. We integrate everything into a single commercial maintenance plan.
Book a Legionella Risk Review
Protect your residents, guests and reputation with plumbing-led Legionella control.