Health, Safety and Environment
Issue Date : 30 / 7 / 2013
SIMS Events waiting for
First Aid Recordable
No. injuries ytd 10 1
No. days worked since
last OSHA recordable
No. days worked since
last RIDDOR injury
What is Legionella – how can it affect us ....
Cases of Legionella have been in the news where people have suffered as a result of catching
the disease from poorly maintained water systems. The reported cases are where people have
been exposed to the bacteria in a droplet form due to some types of air-conditioning units, cooling
tower spray, fountains etc. Legionella bacteria thrives in poorly maintained water systems.
Legionnaires disease is a potentially fatal form of pneumonia which can affect anybody, but which
usually affects those who are susceptible due to age, illness, low immune system, or who smoke.
Hand Injury – first aid
A member of the scaffolding team was hurt last week when a tube dropped
on his hand - checked by X-ray, but thankfully his hand is only bruised.
The bacterium Legionella pneumophila and related bacteria can be found
naturally in water sources such as rivers, lakes and reservoirs, usually in low
numbers. The bacteria thrives in temperatures between 20°c to 50°c.
Temperatures of 60°c and above will kill Legionella.
Legionella was first identified following a large outbreak at The American
Legion Convention in Philadelphia, USA, in 1976 - hence the name Legionella.
It is contracted by inhaling contaminated tiny droplets of water which have become airborne.
The primary legislation for Legionella control is :
Health & Safety at Work Act (1974)
The HSE document L8 “The control of legionella bacteria in water systems: Approved
Code of Practice and Guidance“. sets out practical advice on how to satisfy the legal
requirements of the Health and Safety at Work Act.
What controls do we need to have place....
There are management controls in place within Sembcorp to stop the growth of bacteria within
our water systems. MP 1333 describes the controls in more detail.
Cooling Towers There needs to be a Risk Assessment for each cooling tower. This
will identify the controls which need to be implemented.
• A maintenance, inspection and cleaning regime needs to be
• Chemical treatment of the water to prevent bacterial growth
• Daily dip slides are taken by Sembcorp from the cooling tower
ponds to check that the controls identified above are effective. The
results are documented, and from these tests we identify any
changes required to the dosing regime
• Additional independent samples for legionella are taken by Nalco
and results from these checks are given to the plant management
• Those with specific responsibilities need to be trained
• Those who work in the area need awareness information
Know who the nominated responsible person is …
Power Station = Chris Plews
Buildings = Wayne Evans
and in their absence Jane Atkinson and Geoff Davis
Make sure you are familiar with MP1333
Know where your area Legionella assessment register is located
If high readings are found, control measures will be introduced – comply with
them i.e. – where exclusion zones are established or water systems are
isolated for increased dosing – do not enter or tamper
What do you need to know....
Domestic Water Systems
On a weekly basis all domestic water systems are operated for a short
period and this is documented.
On a monthly basis we check water
temperatures and these results are also documented.
Water samples are checked quarterly by Nalco for the presence of
Legionella. BRLM are notified of any anomalies and corrective measures are immediately put in
What are the requirements for the Legionella bacteria to flourish?
Electron microscope view of legionella
What do you need to do....
Report to your manager if any shower or tap shows a lower temperature
Report any water facilities which are used infrequently i.e. rarely used
such as showers, sinks or toilets, unserviced air conditioning units and
water systems that are not drained regularly
Only go up the cooling towers if you are authorised to do so
If you are working on the cooling towers make sure you are wearing the
Take action on any abnormal results
Check that emergency shower test procedures are being followed