sewage or tanks tanks holding non-potable liquids. holding liquids The system should be protected against by either preventers ST (e.g. vacuum breakers) or air gaps Testable backflow should be tested after installation and at least ST every 12 months or in accordance with the manufacturer’s instructions. The disinfectant halogen residual should be maintained at a minimum ST 4.42 Disinfectant halogen residual of 0.2mg/L and not more than 5.0mg/L of free chlorine in all sites of the distribution system (see also item 4.45). Alternative means of disinfection can be acceptable provided a scientific assessment is conducted to ensure its efficacy is established. 4.43 Coating Coating materials used in the piping system should not introduce toxic ST materials substances the potable water Hygienic practices and procedures for maintenance and repair work 4.44 Maintenance ST should be used. During maintenance or repair the workers should have written procedures for maintenance of piping systems. The relevant section of the system needs to be disinfected following any repair works. 4.45 Maintenance In cold water distribution systems, water temperatures should ideally ST of temperature in be maintained at less than 25°C (77°F) throughout the system to cold water provide effective Legionella control. However, this may not be distribution system achievable in all systems, particularly those in hot climates. Maintaining residual disinfection at >0.5mg/L free chlorine, or alternative disinfection methods and technology, will contribute to the effective control of Legionella in such circumstances.
sewage or tanks holding liquids tanks holding non-potable liquids. The system should be protected against by either preventers (e.g. vacuum breakers) or air gaps ST Testable backflow should be tested after installation and at least every 12 months or in accordance with the manufacturer’s instructions. ST 4.42 Disinfectant halogen residual The disinfectant halogen residual should be maintained at a minimum of 0.2mg/L and not more than 5.0mg/L of free chlorine in all sites of the distribution system (see also item 4.45). Alternative means of disinfection can be acceptable provided a scientific assessment is conducted to ensure its efficacy is established. ST 4.43 Coating materials Coating materials used in the piping system should not introduce toxic substances the potable water ST 4.44 Maintenance Hygienic practices and procedures for maintenance and repair work should be used. During maintenance or repair the workers should have written procedures for maintenance of piping systems. The relevant section of the system needs to be disinfected following any repair works. ST 4.45 Maintenance of temperature in cold water distribution system In cold water distribution systems, water temperatures should ideally be maintained at less than 25°C (77°F) throughout the system to provide effective Legionella control. However, this may not be achievable in all systems, particularly those in hot climates. Maintaining residual disinfection at >0.5mg/L free chlorine, or alternative disinfection methods and technology, will contribute to the effective control of Legionella in such circumstances. ST