Tackling Legionella risk

14 March 2016

Vicky Smedley, delivery manager – water systems, at Develop Training Limited (DTL), discusses the importance of maintenance training to help combat Legionella

Potentially fatal Legionella bacteria and similar hazards in air conditioning and water systems present a health risk to employees and visitors of affected premises. Employers, managers and responsible persons face prosecution if they fail to comply with UK legislation on the subject. 

Maintenance training is essential to control Legionella and other water-borne hazards in air conditioning and water systems. Legionella bacteria presents a real risk for any facility. Recent years have seen outbreaks in hospitals, manufacturing facilities, leisure establishments and garden centres. So, it’s important that you put in place the right steps and measures to protect both the workforce and any visitors from the dangers that surround exposure to Legionella.

The health consequences, including the likelihood of fatalities, increase in facilities where people may have impaired immunity, such as hospitals and care homes. It is crucial that maintenance managers are aware of the dangers and have effective processes and training programmes in place to mitigate them. 

Modern training techniques – such as blended learning which includes a mix of classroom-based learning, e-learning, practical training and onsite mentoring – can ensure that responsible persons are trained more effectively in the maintenance of systems than with traditional, classroom-only training. 

This, coupled with new competency qualifications and compliance processes, gives management flexibility over how and where training is delivered. It also provides them with confidence that maintenance is carried out effectively and monitored properly to ensure the health and wellbeing of building users, as well as compliance with legislation.

Air conditioning units

Despite the requirement for companies to be compliant with the latest regulations outlined in the Health & Safety Executive’s Approved Code of Practice for Legionnaires Disease, it is still an ongoing problem. Air conditioning units can be a haven for this potentially deadly bacteria, so be sure to take essential safety precautions.

It is recommended that air conditioning systems be professionally checked, cleaned and serviced at least once a year. Generally, best practice is to have cooling systems serviced in early spring and heating systems looked at near the start of autumn. This will mean that all units are checked and serviced before the seasons when they are likely to be used a lot, and that contaminants and disease-causing agents such as mould and micro-organisms such as Legionella, do not get the chance to build up to dangerous levels before being cleaned out.

Do not let air conditioning systems sit entirely idle for long periods of time and keep water at a temperature in which Legionella and similar organisms do not thrive well. Typically, this means water should either be heated above 60°C, or cooled to a temperature of less than 20°C.

Once a month during the season, clean or replace the filter, evaporator and condenser coils. Keeping pipe lengths as short as possible or removing redundant pipework will help to avoid water stagnating in the system. It is vital to keep the system and the water in it clean; water samples should be analysed periodically, and if necessary treated, to catch any outbreaks of Legionella before they become a major threat. 

Dry/wet cooling systems

In recent years there has been increasing use of dry/wet cooling systems which are designed to operate both in dry air cooled mode and wet evaporative cooling mode. There are different types of dry/wet cooling systems and these can have a wide range of risk profiles. Detailed training will enable those responsible to evaluate between different equipment.

In organisations that are concerned about the risk of legionella and wish to be sure that they take adequate steps to prevent an occurrence in their premises, training is vital. Inadequately trained operators have been identified as a major reason for the prevalence of water quality incidents and disease outbreaks. Error management techniques put forward as solutions to the problem include selection, training, licensing and certification. 

It is clear that addressing these issues with appropriate management and technician training is imperative for maintenance managers and anyone with a duty of care for at-risk premises.