Since the Government is now advising home working, it is timely to remind you of the Legionella risks in vacant properties, and workplaces which have become less occupied, where water is allowed to stagnate within water systems.
As a general principle,
Outlets on hot and cold water systems should be used at least once a week to maintain a degree of water flow and to minimise the chances of stagnation.
To manage the risks during non-occupancy, consideration should be given to implementing a suitable flushing regime or other measures such as draining the system if it is to remain vacant for long periods Public Health England advise reference to this information
Ensure a good turnover of water, adequate monitoring of control parameters ie: temperature/or biocide levels and inspected for cleanliness also the regular flushing of dead legs, infrequently used outlets and areas of the system where there is poor circulation.
Responsible persons, and/or Facilities Managers, need to risk assess legionella control across all water provision to ensure water quality is maintained and review risk assessments.The current control regime must be maintained if it cannot be delivered then you will need to consider emergency shutdown procedures.
In addition, consideration is required of other water systems that are no longer in use, such asevaporative cooling towers, leisure, sports and swimming and spa pool facilities. Public Health England suggest that for these facilities, you should follow the procedures described in the Pool Water Treatment Advisory Group Code of Practice.
Guidance has also been produced by the European Society for Clinical Microbiology and Infectious disease on managing Legionella in building water systems during the COVID-19 pandemic:
Reference: COVID-19 and Food Water and Environmental Microbiology Services from Public Health England
If you require further information or support in relation to this matterplease do not hesitate to get in touch using the following contact details:
Commercial Team at Mole Valley Valley District Council: Email: Env.Health@molevalley.gov.uk; Telephone number: 01306 885001 or Commercial Team at Tandridge District Council: Email: firstname.lastname@example.org; Telephone number: 01883 722000