The Risk Assessment should be reviewed if: 1)    It is not reviewed regularly.2)    Changes are made to plant or water systems or its use.3)    Changes are made to building use in which the water system is installed.4)    New Information about risks or control measures becomes available.5)    Results of checks indicate that control measures are no longer effective. Once a risk has been identified and assessed, a scheme of control should be prepared for preventing or controlling it. The risk is heightened when conditions are not monitored and control of the system is lost, thereby allowing Legionella bacteria to proliferate. The scheme of control should be implemented together with a planned preventative maintenance schedule, in line with that contained within the general recommendation’s sections of this report. This will meet the requirements of the HSE ACOP L8 (Fourth edition: 2013) and the associated HSG274 guidance documents.The ACOP L8 applies to any work undertaken, and to premises used in connection with a trade. All water systems should be considered, with the potential for both the growth of Legionella bacteria, and water dissemination to atmosphere being assessed. The responsibility for management and maintenance of a system should be defined with clear lines of communication and reporting imposed. A scheme of control or prevention techniques should be applied to minimise the risk areas identified. Records are required to be kept on site at all times for the preceding five years. The ACOP provides the legislation through which prosecution may be made under the Health and Safety at Work Act or COSHH legislation. Whilst failure to comply with the ACOP is not in itself an offence, evident contravention of such may be used in evidence as part of the prosecution case.