HC Legionella (HCLp) are specialists in resolving Legionella control issues. We don’t just say we manage through to resolution; we live it. Our knowledgeable team includes an Authorising Engineer, expert plumbers and water hygiene technicians; this means you get an industry specialist looking at your challenges while our plumbers can give you the mechanical mindset to resolve any issues.

A Legionella control issue can seem as simple as undesired water temperatures; but the root cause behind this can range from a lack of insulation on pipework through to mechanical failure of a circulating loop. No matter the problem we will work with your estates team to manage the matter through to resolution.

On a recent project, HCLp were called upon to provide our expertise when an estates team identified a building with temperature issues; this was a high-risk site with highly susceptible personnel. Our team mobilised within moments of taking the enquiry and arranged to meet the estates team on site the following morning; in the meantime previous site data was shared with our AE to gain a wider understanding of the site and devise a plan of works with our lead Plumbing Engineer.

Upon reviewing the site records it was clear that something had been going wrong for some time; at this point the key focus of the HCLp team was to protect patient and staff safety turning to initial risk mitigation through the use of Point of Use (Pou) Filters giving time to review the system details; these units provide the perfect short term risk mitigation solution breaking the infection pathway to stop any waterborne pathogens, (Legionella, Pseudomonas or other pathogens), from coming into contact with patients.

Before installing the PoU Filters the HCLp approach meant that we took Legionella samples and submitted them to our UKAS Accredited laboratory for testing.

The plumbing team installed the PoU filters within a couple of days, the time afforded by installing PoU filters gave us respite, we had 90 days of protection to remediate the system, we could start to look for root causes of issues and be pro-active in managing the situation; up until this point our role was to make the system safe; now we can re-gain control and manage through to the right resolution for our client.

During filter installation a site wide temperature profiling exercise was completed confirming where control was lost also identifying some potential sources of risk;

• poorly performing subordinate loops
• less than optimal pumps 
• several dead-legs.

All identified dead-legs on site were removed; both on the hot and cold systems, reducing the risk on both and giving the client some assurance that positive progress was being made with reducing risk.

The original data provided by the client and temperature profiling undertaken identified several Thermostatic Mixing Valves (TMV) that did not have full-service history recorded and providing out of specification temperatures; these were fully serviced and re-instated.

The Laboratory reported their results as we planned our next steps; this identified a cluster of results that were delivering >15,000 CFU/L counts of Legionella bacteria. With all of our failing lab results falling on the hot system we knew the hazard was isolated to the hot water system.

Our AE, in discussion with our mechanical plumbers, noticed that when the site was first commissioned it had 10 bedrooms; this had been extended over the years and the pipework just retrofitted to allow for bathrooms and toilets. Within these building upgrades the pipework for the flow and return system had been significantly downsized to feed the extension with flow pipework reducing from 42-22mm at its connection to the original system. This meant that the circulation pipework was now undersized in a large portion of the building, resulting in poor circulating temperatures in this area. This change in pipe size was also found to correspond exactly to the area of the building with significant positive Legionella results. Theoretically we had a resolution.

With agreement from site the hot water supply was shut down for a day to allow works to take place. The flow pipework was increased from 22 – 42mm copper and the return from 15-22mm copper pipework to maintain conditions with the original water system.

To verify the works were successful temperatures were taken at all outlets, pipework temperatures (from the Hot & Cold feeds) for the TMV’s and temperatures of subordinate and tertiary loops, all were achieving desired temperatures throughout.

The system was monitored over the next three months to verify that the hazard was managed and the PoU filters were removed after a third set of Legionella samples delivered not detected results.

Ongoing review meetings with localised action groups including estates, compliance and infection control were regularly held to verify the resolution was effective and the works were satisfactory.

A real example of managing an issue through to resolution.