It needs risk assessing by a competent person.. As for inspection / clean qu - try http://www.hse.gov.uk/pubns/priced/hsg274part3.pdf hope that helps

Definitely requires a Risk Assessment! Under general health and safety law, as an employer or person in control of a premises (eg a landlord), you have health and safety duties and need to take suitable precautions to prevent or control the risk of exposure to legionella. Details of the specific law that applies can be found in part 1 of Legionnaires’ disease: The control of legionella bacteria in water systems. Carrying out a risk assessment is your responsibility and will help you to establish any potential risks and implement measures to either eliminate or control risks. You may be competent to carry out the assessment yourself but, if not, you should ask someone with the necessary skills to conduct a risk assessment. This can be done by someone from within your own organisation or from someone outside, eg an external consultant.