The Necessity of a Legionella Risk Assessment – Case Study


There was no form of Legionella control in this luxury hotel and after an audit from the HSA they were given only 28 days to have a Legionella Risk Assessment carried out with any recommendations to be actioned.

 After contacting ourselves an assessment was carried out immediately with a number non-compliant and high-risk issues noted. Action was taken urgently to ensure the risk of a legionella outbreak was minimized.


5 * Hotel in Munster


After having an audit carried out at their premises in 2020, this hotel was advised by the HSA that it was a legal requirement to have a legionella risk assessment for their site which they did not have. They were given 28 days to make sure a risk assessment was completed.

At the time the hotel did not have a water treatment contractor providing a maintenance programme and so contacted us to have this carried out asap.

We carried out the customer set up while arranging the appointment and reviewing previous documents from site.

The risk assessment was carried out within the next 2 weeks over a 2 day period. The assessment had a “High Risk Rating” as a number of non-compliances had been identified, including:

  • No control scheme is being implemented
  • No management structure identified
  • No one on site had received legionella awareness training
  • Sediment was found in the cold water storage tank
  • CWS was not fitted with a secure close-fitting lid complete with screened lid vent
  • Both inlet and outlet were on the same side of CWS
  • No insulation on cold water storage tank
  • TMV’s had not been checked for a long time

Following the risk assessment, following advice from our Technical Director, the site very quickly addressed any issues to make sure it was operating fully compliantly.

Another Legionella Risk was carried out 3 months after the initial assessment and with all the work carried out the risk factor was reduced to a medium.

Following a review of the site, the HSA gave the hotel a clean bill of health and provided a positive response regarding the timely manner in which the items were addressed.


  • An initial Legionella Risk Assessment, complete with recommendations was carried out immediately. The report was deemed “High Risk” with a number of actions recommended be taken immediately.
    • A site-specific control scheme was designed and implemented by our technical director
    • A management structure was set up to ensure all parties are aware of their duties
    • 5 Members of staff carried out our Legionella Awareness Training
  • The cold water storage tank had a number of non-compliance issues, following our recommendations this was replaced for a WRAS approved tank
  • After remedial works had been implemented a follow up Legionella Risk Assessment was carried out where the risk factor had been reduced to medium.
  • An ongoing maintenance programme was set up with ourselves which includes frequent water sampling , them to ensure their systems were operating safely
  • A detailed programme was put together for site to ensure weekly / monthly check were carried out and recorded by themselves including:
    • Temperature monitoring
    • Inspections, cleaning, descaling and disinfecting any strainers or filters associated with TMV’s
    • Flushing of the system where dead legs have been identified or water flow is low


  • As this was a new client and we had to ensure their set up internally was completed and verified swiftly to make sure remedial works were not delayed
  • The report along with recommendations had to be carried out and completed within a 28 day period, with remedial works started
  • The hotel was still operational with guests so we had to ensure there were minimal disruptions


The risk factor of a legionella outbreak has been greatly reduced and is now being monitored, where any changes will be noticed immediately before there is (if any) any major issue.

Our client now has peace of mind that their water supply is safe and all compliance issues have been resolved. Aquachem had a strict deadline to adhere to, when working as a team we had shown we were able to carry out the required services along with internal set up very quickly.

The HSA concluded their review commenting that all items were actions promptly and that the hotel had satisfied their requirements.


This example show how important it is to have an upto date Legionella Risk Assessment on site at all times. Not only does having this ensure your businesses remains complaint (and satisfies the HSA), you can be certain that your water is safe.

Legionella is easy to control once the correct procedures are in place. While cases of Legionnaires disease are relatively low in Ireland, if that one case is on your premises the repercussions are severe; it’s not worth it.

Contact us today if you need a risk assessment carried out or if you want to find out more.