Handling the dual issues of scalding and Legionnaire's Disease
How the dual issues of scalding and Legionnaire's Disease are being handled around the world
The issues of legionella and storage temperature in water heaters are widely discussed all over the world. Many countries acknowledge that it is a serious issue and deal with it as such. These countries have introduced, or are proposing to introduce, regulations that specifically deal with this issue. A few examples:
As highlighted elsewhere on this site, Canada is currently actively addressing this issue. There is a proposed change to the National Plumbing Code in place that specifies water delivery temperatures should not exceed 49°C (120°F), and a recommendation that turning down the water heater thermostat is not turned down due to the potential for legionella bacteria growth.
- The Netherlands
Following a significant outbreak of Legionnaire's disease in The Netherlands some years ago, wide ranging regulations and controls specifically dealing with the Legionella issue were implemented. The national plumbing standard and regulation authority, Kiwa, has a range of information on this issue on its web site (www.kiwa.nl). The aggressive manner in which this country has addressed this issue, and specifically water storage temperatures, highlights their level of concern on the subject.
The National Plumbing Code (AS3500) specifies a storage temperature of greater than 60°C (140°F), with a delivery temperature not to exceed 50°C (122°F). There was sufficient concern regarding the dangers of Legionella and scalding to specifically address the issue in the national code (which has since been implemented via regulations in each state).
The United Kingdom is currently addressing the dual issues of scalding and Legionella. While regulations are yet to be implemented, there is considerable work going on behind the scenes. It is expected that in the near future both the Legionella issue and scalding will be addressed via formal regulations. The issue is being addressed by the Building Research Establishment (BRE, www.bre.co.uk) for the Department of Transport, Local Government and Regions (DTLR). Again, a high water storage temperature of 60°C (140°F) or higher is central to the proposal.
A regulation requiring water to be heated to at least 60°C (140°F) but delivered at 50°C (120°F) or less has been proposed in France. The exact status of this regulation implementation is unknown at this time. The French national standards organization, AFNOR (www.afnor.fr), and the national testing authority, CSTB (www.cstb.fr), are both heavily involved in this process. Again, the activities of France to deal with water storage and delivery temperatures indicates a strong concern over both scalding and Legionella.