We received an enquiry for legionella samples to be taken from a Leisure Centre which had been closed over the Coronavirus lockdown period, and duty holder wished to re-open. Acquiesce Environmental Compliance swiftly attended site to collect samples for analysis in a UKAs accredited laboratory. Upon receiving these results we identified potentially lethal legionella SG1 bacteria within the system. We proceeded to carry out a full legionella risk assessment and through investigation. As soon as the bacteria was identified, point of use filters were fitted to outlets, so that the building could open, and water could safely be used by service users and staff.
During the legionella risk assessment, significant dead legs were identified in the roof void. These lengths of pipework have no outlets and used to feed sinks & wash hand basins. When these have been removed, the plumber has capped off the pipework, leaving a significant risk in the system. These lengths of pipework will contain stagnant water, which will provide an environment suitable for bacterial growth. Once the pipe fills with bacteria, it can then potentially spread into the system. These were quickly removed.
Further into this investigation, we identified an issue with the expansion vessel, which was fed from the hot water return, rather than cold water with no check valve fitted. The vessel had a drain valve fitted to enable regular flushing, however this had been fitted in the wrong place, meaning the entire contents of the unit could not be drained.
When we isolated and drained the unit, the temperature recorded was 34c, which is close to the optimum temperature for bacterial growth of 37c. A decision was made to sample this water. When we received the results, we found SG1 legionella bacteria at 50 x the levels we had in the building. This vessel was then moved to be fed from cold water, the drain valve repositioned, and a check valve fitted to confirm to water regulations. The flushing of this unit was then added to a quarterly regime, as Acquiesce Environmental Compliance was awarded the on-going control scheme monitoring contract for the site, following the excellent work which had been completed.
Following more remedial works, dead end removals, fitting of backflow protection devices, a full hot & cold water system disinfection was carried out. 72 hours after completion of this disinfection, further legionella samples were taken. These come back from our UKAS accredited laboratory all clear. A sampling regime was put in place to check conditions and safety of water supplies for building users & staff. The water system here are now safe for people to use, and a happy customer too! For more on what we do, please call 0121 608 3272 or email firstname.lastname@example.org