With regard to the requirement to carry out a risk assessment we would point you to the requirements from L8 advising that before maintenance procedures can be implemented a full and thorough assessment must be carried out.

This will asses the physical condition of the services, their operation, the occupancy of the building and the effect that this will have on the potential for colonisation and dissemination of the legionella organism to a susceptible population.

If the systems have not been fully assessed then the implementation of control measures and their effectiveness is uncertain as the condition and operation of the system is unknown.

Sampling under these circumstances merely confirms the presence or otherwise of the organism at a specific point in time, it does not provide any means of minimising the potential for colonisation and dissemination in the first instance, which is the thrust of the legislation. The assessment may highlight if some of this expenditure is better used elsewhere.

A legionella risk assessment is required regardless of the building size.

The assessment should be reviewed every two years or if the use, occupation, fabric of the services of the building or new legislation is introduced. This does not necessarily mean a completely new assessment be carried out, rather that it is reviewed in light of any changes and updated appropriately.

The assessment will then be the driving force in setting up a tailored planned preventative maintenance program for each site, which must be kept in a formal site logbook and regularly reviewed and maintained.

With regard to cleaning and disinfection of the water storage cisterns and down services L8 requires that the tanks be inspected regularly and a judgement made on whether cleaning and disinfection is required. Due to the subjective nature of this inspection many organisations now carry out routine cleaning and disinfection of their tanks and systems on an annual basis. And it appears to be becoming good practice to do so.

If however this is not to be the case then the onus is on the responsible person(s) and statutory duty holder and their deputies to ensure that the water is of potable quality. Microbiological sampling for TVC’s (Total Viable Counts) and e-coli and coliforms as well as visual inspection can assist in the decision if cleaning and disinfection is required. However as we have stated this is no substitute for a properly designed system with appropriate planned preventative maintenance.

In buildings which contain a high proportion of elderly or potentially unhealthy people who are therefore more susceptible to potential pathogens than the general population the implementation of as assessment and maintenance plans cannot be overemphasised.

As we discussed the L8 ACOP is a guidance note but failure to comply with it can lead to prosecution under the Health and Safety at Work Act 1974 and COSHH.