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What is legionella?

Legionnaires’ disease is a potentially fatal pneumonia caused by legionella bacteria. Here are some of the facts:

  • This is the most well known and serious form of a group of diseases collectively known as legionellosis
  • The inhalation of small droplets of water contaminated by the bacteria may give rise to infection
  • Legionnaires’ disease is considered an environmental disease because its causative agent (legionella) is transmitted from an environmental source (water) to a person
  • Legionella bacteria are common in natural watercourses such as rivers and ponds
  • The Legionella bacteria may also contaminate and proliferate in other water systems such as cooling towers, hot and cold water systems, humidifiers and spa baths.
  • Outbreaks of legionnaire’s disease have occurred in or near large building complexes such as hospitals, hotels, office blocks and factories. Other areas are public buildings, sheltered accommodation, garden centres, sports centres and cruise liners.
  • Cooling towers can produce droplets and if there is an air current to carry them a distance, and often being located on roof-tops, there is a potential to infect large numbers of people

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“We would like to take this opportunity to say how impressed we are with the standard of work carried out at the school. The team went about their business in a polite and professional manner, arriving on time and ensuring that the site was clean and tidy when they left. We would certainly recommend Envex in the future.”

Denefield school, Trinity school, Spurcroft school

“We have used Envex Health, Safety and Risk Consultants for all our Legionella remedial works and safety maintenance checks for since April 2009, and are very happy with their work and would recommend them to other schools.”

Karen Hobbs – School Business Manager, Downsway School

Controlling the risk from legionella

The key aim is to prevent or control the growth and multiplication of legionella through effective design, maintenance and operation of water services. Controlling the risk from legionella in water systems requires:-

  • Good design
  • A suitable and sufficient risk assessment
  • An effective legionella management policy with responsibilities documented and
  • An effective written scheme
  • a trained Responsible Person appointed with the time and resources to deliver the written scheme and/or work with competent contractors.

A written scheme of intended legionella risk control should describe:

  • The water system, including an up-to-date plan or schematic diagram
  • Who is responsible for conducting the assessment and managing its implementation
  • The safe and correct operation of the system
  • What control methods and other precautions will be used
  • The checks that will be carried out on the control scheme and how often these checks will be carried out
  • Appoint a “responsible person” with responsibility for implementing and managing the scheme
  • Keep records and check that what has been done is effective

Legionella risk assessment

Trained personnel use the independent Building Services Research Institute Association (BSRIA) system as the basis of a protocol to undertake legionella risk assessments.  This will allow you to understand where you are with respect to current levels of risk and compliance;  the assessment comes with a prioritised action plan for remdial works and the key tasks for a written scheme for future control.

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Remedial works service

Implementing remedial works is the first part of getting control. Envex have partnership arrangements with contractors we have approved in order to make this process simple for our clients. We have negotiated discounted rates to allow us to manage the delivery of this work without the client incurring greater costs. This is an optional service which we now provide based on demand from clients. We ensure that you get what you need and that the work is specified and delivered properly.