What does augmented care mean for legionella control?
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Key points
- Augmented care is the HTM 04-01 term for clinical areas where patients are highly vulnerable to waterborne infection: intensive care, neonatal, transplant, haematology/oncology, burns and some renal units.
- The water itself is part of the exposure route, so the tolerated bacterial count at the outlet is effectively zero.
- Controls go beyond the standard regime: a water safety plan and group, outlet sampling for pseudomonas, and point-of-use filters as interim barriers.
- Named roles apply, including an independent authorising engineer (water) who audits the arrangements.
- Ordinary care homes usually work to HSG274 and ACOP L8; augmented care is the hospital-grade standard.
Augmented care is the HTM 04-01 term for hospital areas where patients are highly vulnerable to infection from water: intensive care, neonatal, transplant, haematology and oncology, burns and some renal units. There, water systems are managed to a higher standard under a water safety plan, with tighter monitoring, pseudomonas controls and point-of-use filters where needed.
What augmented care actually means
Augmented care describes clinical settings where patients are especially susceptible to infection from the water supply. The term covers areas where patients are severely immunosuppressed, where the skin barrier is breached, or where invasive devices are in use. In practice that means intensive care and high dependency units, neonatal units, transplant units, haematology and oncology wards, burns units, and some renal units.
The logic is direct. In most buildings, water hygiene protects people who could fight off a low-level exposure without ever noticing it. In augmented care the patients cannot. Water from a tap or shower can reach an open wound, a central line site or a ventilated lung, and an organism that would be irrelevant to a healthy person can cause a serious hospital-acquired infection. The water system stops being a building service and becomes part of the patient's exposure pathway.
The framework: HTM 04-01 and the water safety plan
The governing document is HTM 04-01, the Department of Health and Social Care guidance on safe water in healthcare premises. Part A covers design and commissioning, Part B covers operational management, and Part C adds specific advice on Pseudomonas aeruginosa in augmented care. Our HTM 04-01 explainer sets out the whole structure.
Under HTM 04-01 each healthcare organisation runs a water safety plan, a whole-estate risk-management document in the World Health Organization mould, owned by a multidisciplinary water safety group. Estates, infection prevention and control, microbiology, clinical staff and the specialist water roles sit on it together. The group reviews the monitoring, including the augmented-care outlet results, and decides what action a positive or drifting result requires. That group governance is the defining difference from general premises, where one responsible person may carry the whole scheme.
The organisms being controlled
Legionella remains the headline organism, and the healthcare temperature regime is the strictest version of it: hot water stored at 60°C and reaching 55°C at the outlet within one minute, cold below 20°C. But in augmented care legionella is not alone on the risk register.
- Pseudomonas aeruginosa colonises the last few centimetres of taps and outlet fittings and can transfer directly to patients during washing and clinical care. It is the reason Part C exists.
- Stenotrophomonas maltophilia behaves similarly as an outlet-dwelling opportunist affecting immunocompromised patients.
- Non-tuberculous mycobacteria persist in biofilm and tolerate chlorine well, so they survive regimes that clear other organisms.
The shared habitat is biofilm, which is why augmented-care control is as much about the physical condition of outlets, hoses and valves as it is about chemistry.
The controls in practice
On top of the standard hot and cold water regime, augmented care adds a layer of outlet-level control:
- Regular sampling of outlets for Pseudomonas aeruginosa on the schedule set by the water safety plan, with legionella sampling alongside it. Results go to the water safety group, and every positive result gets a recorded response.
- Point-of-use filters as an interim barrier. A 0.2 micron membrane at the tap or shower physically retains legionella and pseudomonas while the underlying contamination is investigated and put right. Our page on point-of-use water filters explains what they do and, just as importantly, what they do not do.
- TMVs as controlled assets. Because augmented-care patients are also highly vulnerable to scalding, outlets are blended, and those valves are serviced and checked on a documented schedule rather than fitted and forgotten.
- Flushing of little-used outlets so no tap or shower sits stagnant, which in a ward context means a deliberate, recorded flushing regime for any outlet not in daily use.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
The people: named roles and independent scrutiny
HTM 04-01 names a chain of roles: the duty holder at board level, the responsible person (water) running the scheme day to day, authorised persons doing the operational work, and an authorising engineer (water) who sits outside the line and audits it all independently. In augmented care that independence matters most, because the consequence of a drifting control is not a paperwork gap but an infection in a patient who cannot fight it.
In augmented care the outlet is part of the treatment pathway: the water itself can reach the patient, so the tolerated bacterial count at the point of use is effectively zero.
What this means outside a hospital
If you run a care home, a hospice or a supported-living setting, the honest position is that HTM 04-01 is written for healthcare premises, and most care settings work to HSG274 and ACOP L8 instead, as our page on legionella in care homes explains. The Care Quality Commission expects regulated providers to manage water safety properly under that framework. The augmented-care approach is still worth understanding, because where residents are highly dependent and clinically vulnerable, its disciplines, a written plan, outlet-level attention and recorded flushing, are the defensible standard to borrow from. What it never does is let anyone relax: recording controls is how you evidence them, not a substitute for carrying them out.
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
Frequently asked questions
What is an augmented care unit?
Augmented care is the HTM 04-01 term for clinical areas where patients are highly vulnerable to infection from the water supply: intensive care and high dependency units, neonatal units, transplant units, haematology and oncology wards, burns units and some renal units. In these areas organisms in the water, including legionella and Pseudomonas aeruginosa, can reach patients directly, so the water system is managed to a higher standard than elsewhere in the hospital.
What extra legionella controls apply in augmented care?
Everything in the standard healthcare regime, run more tightly: hot water reaching 55°C at outlets within one minute, thermostatic mixing valves maintained as controlled assets, flushing of little-used outlets, and a written water safety plan owned by a multidisciplinary water safety group. On top of that, HTM 04-01 Part C adds Pseudomonas aeruginosa sampling at outlets, and point-of-use filters are used as an interim barrier where an outlet is found to be contaminated.
Does augmented care require water sampling?
Yes. Where general premises sample for legionella on a risk-based schedule, augmented care areas are expected to sample outlets for Pseudomonas aeruginosa regularly under HTM 04-01 Part C, with prompt, recorded action when the organism is found. Legionella sampling sits inside the water safety plan as well. Results go to the water safety group, which decides the response as a team rather than leaving it to one person reacting to a result.
What is the role of point-of-use filters in augmented care?
A point-of-use filter is a 0.2 micron membrane fitted at a tap or shower that physically retains legionella and pseudomonas, giving immediate protection at that one outlet. In augmented care it is used as an interim measure while the underlying contamination is put right, never as a substitute for the temperature regime or the water safety plan. Filters have a rated life and must be changed and recorded on the manufacturer's schedule.
Does HTM 04-01 apply to care homes?
HTM 04-01 is written for healthcare premises such as hospitals. A standard residential care home usually manages legionella under HSG274 and ACOP L8 instead, though the Care Quality Commission expects regulated providers to follow good practice consistent with the healthcare approach. Where a setting delivers genuinely clinical care to highly vulnerable residents, the augmented-care mindset of tighter control and a water safety plan is the defensible standard.
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