Legionella risk assessment services: what you are actually buying

This work is mostly sold through relationships, regulatory pressure and renewals rather than through open comparison, so the buyer usually arrives with little to compare against. This article is the comparison.

What the service consists of

A walkdown of the building’s water systems with the drawings in hand. An inventory of aerosol-generating equipment. Measured temperatures at defined points rather than plant room assumptions. Identification of stagnation: dead legs, low-use outlets, idle equipment. And a written record of findings specific enough that someone else could act on each one without phoning the assessor.

What the deliverable should look like

A document about your building and no other. Named locations, not floor-level generalities. A corrected schematic, or at minimum a marked-up one. Findings ranked in some defensible order, each with a named owner. Its own review date, and the events that bring the review forward. If the deliverable would read the same with another building’s address on the cover, it was not an assessment of yours. How that happens, and what a form can and cannot carry, is in what a risk assessment template holds.

Six questions to ask before engaging anybody

1. Will you physically walk the whole system, including roof and plant rooms?
2. Do you correct the schematic where the building disagrees with it?
3. Which standard or guidance will you assess against, and why that one for this building?
4. Who writes and signs the findings, and what are their qualifications?
5. Do you sell anything the findings could recommend?
6. What, specifically, will the document let my maintenance team do differently?

The fifth question is the load-bearing one, and it gets its own section.

The conflict of interest to check for

An assessor who also sells water treatment, remediation or equipment has a structural reason to find work for the other side of the business. That does not make any individual assessment wrong, but it makes every recommendation in it worth reading twice. The same separation argument is made for cooling towers under cooling tower Legionella testing and in cooling tower water treatment and legionella.

Where sampling fits, and where it does not

An assessment is not a sampling round, and a provider who answers a risk assessment enquiry with a quote for samples has skipped the step that gives the samples meaning. The assessment establishes where sampling would be informative and what a result would be compared against. The sampling itself, and what happens to the sample afterwards, is described under sampling and analysis.

The local layer

What a facility is required to have varies by state, by city and by facility type, and in some places specific equipment carries registration and reporting duties of its own. A competent provider establishes which requirements apply to your building before writing anything, because the requirements decide what the document has to demonstrate. The background to the exercise itself is covered in what a risk assessment covers.

What no provider can promise

That the building is safe, permanently or at all. An assessment is a description of conditions on a day, and the honest version says so on its cover. Anyone promising a clean bill of health is selling reassurance, which is not a deliverable. And as everywhere on this site: if your concern is a person rather than a building, the right call is a doctor, not an assessor.