Technical Note
2 total works
TN 2/98
Hot and cold water services account for most cases of legionnaires' disease in the UK, and treatments such as chlorine dioxide and ionisation have increased in popularity with the realization that a temperature regime is not always achievable - or effective. This text describes an experiment to directly compare the efficacy of a temperature regime against chlorine dioxide treatment, using a plant that represents a typical installation rather than best practice. It supplies and discusses the detailed results, which suggest that the maintenance of hot water at 60C flow and 50C return does not provide complete protection against the survival of legionella.
TN 6/96
This publication is the second in the BSRIA series on legionaires' disease (Ref 8). It is specifically concerned with hot and cold water services, which continue to account for the majority of identified cases of legionnaires' disease in the UK. Technical guidance on reducing the risk of legionellosis in the UK was introduced by the Government in the early 1990s in the "Health and Safety" series booklet, HS(G)70, Ref 1. This was first issued in 1991 and subsequently revised in 1993 in order to relect a greater awareness that a temperature regime for controlling legionella bacteria was not always achievable and other methods of water treatment, such as ionization, could be used if they could be shown to be as effective as a temperature regime. In 1994, BSRIA set up a research project to assess the effectiveness of ionization at reduced water temperatures against a temperature regime for the control of microbiological contaminants, including legionella bacteria in hot and cold water systems. The project results showed that whilst a temperature regime still remains the primary method of control advocated in HS(G)70 there a number of concerns regarding its efficacy.
In particular, the results highlighted the potential problems of using a temperature regime for hot and cold water systems, and compared these to ionization. The results of ionization water treatment showed that it can be an effective strategy in hot and cold water installations provided that the application is properly assessed and designed as part of an overall water treatment regime by reputable and experienced companies.
In particular, the results highlighted the potential problems of using a temperature regime for hot and cold water systems, and compared these to ionization. The results of ionization water treatment showed that it can be an effective strategy in hot and cold water installations provided that the application is properly assessed and designed as part of an overall water treatment regime by reputable and experienced companies.