Legionella, what is it?

In order to describe what a Legionella risk assessment is it is important to explain what Legionella is. Legionella is a Gram -ve bacteria capable of causing a potentially deadly infectious pneumonia type sickness known as Legionellosis.  The micro organism thrives in all water in between the temperatures of 20 C and 45 C.  Any age range can be susceptible to  Legionella infection if living or working in an environment of high risk.  Additionally , men over the age of 50, in particularmen who smoke cigarettes or have immune suppressing illnesses, are statistically at higher risk of an infection.

Legionellosis has two forms; Legionnaires’ disease and Pontiac fever. Legionnaires’ disease causes pneumonia and can be fatal, whilst Pontiac fever is a much less severe disease with symptoms similar to those of a bad cold and is not deadly.

Threat of Legionella Infection from Domestic Water Systems

Legionella can be found in high concentration inside man-made water supply systems such as hot & cold domestic water pipes and within industrial process pipework.  If conditions are suitable the Legionella can multiply and colonise the system, increasing the risk of Legionnaire’s disease , particularly if the water system is linked to a shower or spray tap, as it is in these situations that humans can become infected with Legionella by inhaling contaminated water droplets or aerosols.

The risk of acquiring a Legionella infection from water systems , particularly within the work place , has been considerably reduced by tighter health & safety regulations being enforced.  The Health & Safety at Work Act 1974 and the Control of Substances Hazardous to Health or COSHH Regulations 2002 ensure that employers maintain their water systems to high enoughlevel so as to keep infections to a minimum .

Legionella Risk Assessment Providers

Legionella risk assessment providers commonly offer a program of services that minimise the risk of Legionella infection by ensuring that guidelines are met. First of all they would carry out Legionella risk assessments which would assess the risk of infection linked to the water system.  This would involve a thorough examination of the water system to include the source of the water, if there was stored water on site such as water tanks or water heaters, what outlets werepresent and how often these were used, the type of individual who may come into contact with the water system and how the water system was currently being managed to prevent the risks from Legionella. 

Once the Legionella risk has been performed it is then possible to develop a routine inspection and testing plan to further prevent the risks .  This can include routine temperature testing, Legionella sampling, cleaning and chlorination and must include keeping records .

A good Legionella assessment should allow the companies own members of staff to put into action a Legionella control program in order to manage the Legionella risk themselves.   Most Legionella assessment companies can also provide training of members of staff to ensure they are clear about their responsibilities and can effectively carry out the Legionella management tasks that they have been assigned.  They can also be trained to be able to carry out Legionella risk audits to sustain the effectiveness of the in-house Legionella control progrram.