Water commonly contains bacteria from the legionella family. Some of these bacteria can result in serious diseases including Legionnaires Disease. Legionnaires Disease, particularly in vulnerable groups, does result in serious illness and fatalities. For the bacteria to enter the body and cause harm they need to present in fine aerosols such as those encountered in showers.
To control legionella growth in building water systems the basic control philosophy can be described as,
• Keep it clean. Legionella thrives in scale, slime and other hard surface contamination.
• Keep it moving. Legionella does not thrive in moving water which is why slow moving or static water, such as found in dead legs should be avoided.
• Keep it at the right temperature. Legionella does not grow below 20 C and is killed above 60 C, and these temperatures are key to controlling legionella.
The water management programme is managed by Estates and Facilities (EAF), using specialist contractors where required. In some cases e.g. specified laboratory emergency eye wash stations, laboratory staff will undertake some system flushing but only as instructed by EAF with records forming part of the overall University water management records.
HSE Legionella and Legionnaires' disease web site includes Approved Code of Practice and guidance http://www.hse.gov.uk/legionnaires
The Control of Substances Hazardous to Health Regulations 2002 (as amended)