OK. Explain to me just what water sampling is?

Universally-speaking – and routinely enveloping a host of sectors, nevermind more medical-related logistical reasoning - samples tend to provide experts with circumstantial evidence to determine whether or not bacteria is present in a range of substances. The water treatment industry is no exception in this regard. On the contrary in fact, as dedicated water sampling allows maintenance staff (and those tasked with the responsibility for safeguarding against legionella manifesting in the workplace) to ascertain if traces of the water-borne bacteria is present in stored water on a client/employer’s premises. Historically encompassing the two key stages, water sampling for legionella ordinarily includes the initial extracting of a sample, subsequently followed by the laboratory analysis of said sample. Both parts of which are performed in compliance with the British Standards and Guidance and European and UK Legislation.

It’s this rudimentary identification and assessment of water derived from water-based systems – which have habitually found to be prudent to encouraging the inception of legionella – which are facilitated by various businesses, which is the imperative first step in establishing if the bacteria exists. Be it water cooling towers, storage tanks or more complex systems, many structures incorporate a labyrinth of pipework too, all of which requires close and regular monitoring to ensure that legionella doesn’t get a foothold from the outset. As you’re no doubt aware, legionella can not only survive but prosper in water temperatures within the 20 – 45 degrees Celsius range; and essentially where water remains stagnant. Therefore it’s critical that experts obtain water samples from source, so that they can be taken back to laboratories for comprehensive analysis and whereby the general levels of bacteria can be closely monitored. This type of testing will concur if bacterial control is being achieved and confirm the likelihood of legionella developing as per the current conditions.

Why Do I Need to Take Water Samples?

The simple answer reads like this. Water testing for legionella affords company/business/organisation owners on-going peace of mind, together with satisfying their legal obligations/duty of care to employees. Notably, by safeguarding against legionella taking hold or, if it already has, to help combat it at this juncture. Plus, being proactive is far more beneficial to all parties concerned as opposed to being reactive. In Layman’s terms, testing water – which has been standing or possibly impacted by a change in optimum legionella-avoiding temperatures - for any traces of the potentially public health-compromising bacteria is, arguably the first line of defence against its spread; and the future presentation of Legionnaire’s Disease. As a tried and tested means of ensuring accurate detection, there are various protocols, procedures and practices to adhere to during the water sample collecting and transportation stages, while stringent analytical techniques and measures also need to be put into place by those individuals/organisations charged with this responsibility. Altering in turnaround times, sensitivity and specificity depending on circumstances, there are a few well-documented ways in which water testing for legionella can take effect, with a broad outline of the way we choose to do things cited under the next heading.

So, Why Would I Choose To Arrange Sampling?

Ideally because the operational practices of your business/organisation means that you are responsible for the health and wellbeing of individuals within your employ. Ergo if the very nature of your business necessitates a water system which stores water for a significant period of time (and potentially at risk of changing temperature with little or no forewarning), then the chances are this could provide a breeding ground for bacteria such as legionella. Which in turn might pose a health threat to employees and third parties, who utilise and/or come into contact with the water-borne bacteria during their vocational duties/part of their acknowledged remit. Other scenarios, in which the question of sampling could crop up, typically include if and when revisions are made to the water system, pipework or assets or if/when an existing water system experiences a change of use. Please note however, any form of testing in relation to legionella concerns should only ever be instigated and carried out in the aftermath of a thorough environmental assessment; and once a sampling plan has been created.

In Summarised Form, What Generally Constitutes the Correct Process for Sampling at Outlets?

As pointed out above, there’s no hard and fast criteria re: water testing for legionella, as many water treatment providers follow slightly different formulas as such. Starting with our own plan of action however, this is how we go about undertaking water sampling at outlets;

• Taking a sterile water sample bottle for collection purposes, the sample is quickly – and safely – secured; ensuring that the vessel doesn’t come into contact with a tap or any other potential contaminants
• The sample then has the relevant labels applied before being transported to a UKAS-accredited laboratory for analysis. This stage happens within 24 hours, while the sample will maintain a low temperature by way of a cool box or refrigerator during transit
• A worksheet will be completed on behalf of the client by the engineer/member of maintenance staff responsible for this procedure; with copies kept for our own records
• 10 days after the initial water testing was actioned, sample results will be made available and subsequent certificates issued/uploaded to our online portal
• Liaison with the site contact will quickly follow in the event of any contaminate being identified during the water sampling process, together with the offering of advice on what remedial actions/plan of action is required going forward

Scrutinising the actual physicality of the water testing for legionella process a little more broadly, and it’s worth observing the following criterias which are more commonly applied;

• Always wear gloves and, should it be needed, respiratory protection when extracting water samples
• Frequent sample bottles which contain a sufficient type - and recognized volume - of neutralizer for any disinfectant agent in the water system; and as provided by the analytical laboratory
• Don’t overfill sample bottle as it could rinse out neutralizer
• Endeavour to collate a ‘pre-flush’ sample of the first water drawn when it comes to bottom drains and outlet valves of storage tanks, sumps, and water heaters (inc, faucets and showerheads)
• In the above instances, always allow water to run until temperature stabilizes, prior to obtaining a second ‘post-flush’ sample once the water temperature becomes constant.

For further information on controlling and monitoring the risk of legionella, check out our free legionella compliance guide.