Assessing legionella risks

Richmond Hydro-Chem has developed a scheme to help clients protect against the risks of legionella. The scheme has been devised using sources from BSRIA, looking at the function of O&M manuals and application guides on legionella maintenance, as well as considering revised CDM regulations. The package includes asset surveys of items such as water tanks, cylinders and point-of use outlets, a written assessment of legionella risk and a ‘suitable and sufficient’ maintenance plan, complete with 12-month log booklet. Initially, schematic drawings are reviewed for good practice. Attention is paid to details such a full-bore flushing valves at the base of cylinders and access for temperature checks at the hot and cold inlet of mixing valves. Installation contractors are provided with as-fitted drawings of domestic water services, including details relevant to the legionella maintenance scheme. Clients benefit because they do not need to outsource a risk assessment of their new building within the defects liability period. Maintenance companies can tender the works without misunderstanding of minimum requirements.