Knowledge of the operation and maintenance, coupled with the knowledge of Legionella growth, has illustrated the importance that commercial premises should carry out such checks. These are stipulated on L.N. 5 (2006). The operation and maintenance of water systems involves frequent visual inspections, regular cleaning and in some cases water treatment processes. Inspections need to be carried out at least once a month and must be used as a guide to the efficacy of the system performance. This responsibility lies with the owner or occupier of the premises and must make available these checks to any auditor or the competent authority.
As stipulated in Regulation 11 (1) (f) Legionella testing has to be carried out at least once every six months by an ISO accredited lab for testing and reporting on Legionella from both the hot and cold water systems.
It is important to note that microbiological monitoring of water systems for Legionella should never replace good engineering practices, regular maintenance and cleaning programs. Testing is a REQUIREMENT in ADDITION to water engineering. Legionella testing is also important in validation testing prior to the commissioning of the water system. The number of samples required will vary depending on the size and nature of the water system but as a guide should have a minimum of weekly samples for 4 to 6 weeks collected from cooling towers and 4 to 6 sets of samples collected on a fortnightly basis from 2 or more locations within warm water system. The verification process could be extended for warm water systems, in particular, by taking samples for measurement of heterotrophic bacterial counts.
It is important to note that Legionella testing requires a maximum of 10 days incubation according to ISO 11731, allowing for unacceptable delays in the event of an outbreak. This further corroborates the fact that inspection, cleaning, decontamination or decommissioning of a system should take priority.
It is also recommendable that total heterotrophic counts are taken on a regular basis, in order to be able to detect bacteria present in biofilms within a system. The presence of such bacteria would be an indication of incorrect or insufficient water disinfection and will require action to be taken well before the detection of Legionella.
According to regulation 12 (1) the responsible person (Owner or manager of the establishment) must ensure that the actions following microbiological analysis for Legionella of hot and cold water services are in accordance with the procedures laid down in Schedule 4 of the L.N. and shall immediately inform the health authorities of the situation as required.
We are the ONLY private local lab that can provide Leigionella testing according to L.N. 5 (2006). the same legal notice stipulates that testing and sampling needs to be carried out by qualified personnel in a ISO 17025 lab.
Apart from this MLSBioDNA will be able to provide risk assessment reports and help its clients, by providing several documentation reports and forms, which need to be kept in a form of a logbook to be presented on the event of an inspection by the authorities.