Schematic drawings are an important part of the prevention of legionella bacteria. According to the Health & Safety Executive, you must take the necessary steps to prevent the risk of legionella in your water system. However: “If you identify a risk that you are unable to prevent, you must introduce a course of action i.e. a written control scheme, that will help you to manage the risk from legionella by implementing effective control measures”. One of these measures is to develop a schematic diagram that will aid the responsible person in managing the risks and implementing checks.
Schematic drawings are basically a simplified but accurate diagram of a system and its associated parts. They are not technical drawings, but they give an illustration of the plant and equipment as well as an indication of the scale. They are intentionally simple to allow anyone without specialist training or experience to understand them quickly and easily. When it comes to your water system, schematic drawings are designed to show the components that are potentially relevant to the risk from legionella, such as strainers, filters, outlets and out-of-use parts.
The drawings must be reviewed and updated whenever you make any changes to your water system, such as adding a new item of equipment that needs to be plumbed in. Your schematic drawing must also be reviewed if there are any changes to the use of your premises, if you receive new information about risk, there is a positive test for the legionella bacteria, or if there has been a case of legionnaires’ disease.
The HSG274 Technical guide Part 2 states that the schematic plan must show: “the layout of the system(s) and its location within and around the premises – this should identify piping routes, storage and header tanks, calorifiers and relevant items of plant, especially water softeners, filters, strainers, pumps and all water outlets”.
How does a schematic drawing help?
Once you have a clear layout of your water system, you will be able to identify any problem areas. This will enable you to manage risks, enabling engineers to be effective when disinfecting and cleaning your system, as well as carry out any remedial works and disinfection.
As part of our services, we can produce or update your legionella schematic drawing which should be kept with your water logbook. Contact us for more information or to arrange an appointment.