Emergency disinfection of the cold water potable water system shall be achieved by the following halogenation procedure:
The Legionella water management plan shall include a written water treatment plan for control of microbiological activity, scale and corrosion. The water treatment plan shall:
The Legionella water management plan shall include:
The Legionella water management plan shall include procedures to be followed if there are suspected Legionellosis health problems associated with the use of potable water in a building system. The plan shall include any directions given by state and local health department authorities. When an outbreak of Legionellosis has been associated with a potable water system or suspected cases of the disease occur, disinfection shall be performed. These procedures shall include criteria for when and where to test for Legionella in the potable water. The method of emergency disinfection shall be thermal or chemical or any combination. Point-of-use filtration (0.2 micrometer) may be used for Legionella control at specific taps and faucets.
Note: Emergency disinfection of hot and cold water systems is potentially hazardous and can cause increased corrosion rates in the potable water system. Routinely performing these procedures can significantly impact equipment/piping lifecycles and is therefore not recommended.
Note: Combining heat and flush disinfection method and chemical disinfection method is the most effective method of emergency disinfection.
Note: After emergency disinfection, re-colonization is likely to occur unless proper temperatures are maintained or a continuous disinfectant residual is maintained or other design/maintenance conditions that caused the problem are corrected.
Note: Point-of-Use filtration does not disinfect a system. It provides hazard control at the point of use only.
The Legionella water management plan shall include the:
• monitoring method and frequency of temperature measurement in the hot and cold water systems. Note: Water temperature recommendations for Legionella control are as follows: hot water heater outlet temperature at or above 60°C (140°F); hot water temperature at coldest point in hot water heater, storage tank or distribution system at or above 51°C (124°F); cold water temperature in any part of system at or below 25°C (77°F). If the Legionella water managementteam determines that these temperatures cannot be achieved, then it may find that additional hazard control measures are required.
An effective method for emergency disinfection of contaminated hot water systems is thermal shock treatment to be implemented using the following procedure:
An effective method for emergency disinfection of contaminated hot water systems is shock halogenation to be implemented using the following procedure:
The Legionella water management plan shall include a written startup plan that includes:
This section describes requirements for cooling towers and evaporative condensers.
Note: In addition, recommendations and guidance on the design, maintenance, and operation of cooling towers and evaporative condensers are provided in ASHRAE Guideline 12 and in the chapter on water treatment in the ASHRAE Handbook—Applications (see Bibliography in Appendix A).
Note: Other resources include Association of Water Technologies (AWT) and the Cooling Technology Institute (CTI). See Appendix A, Bibliography.
With 35 years of experience designing plumbing and mechanical systems for several major architectural, engineering, and design & construct firms. He has designed plumbing, mechanical, and fire protection systems for all building types including airports, stadiums, industrial manufacturing facilities, office buildings, commercial and retail buildings, hospitals, laboratories, prisons, jails, hotels, apartment buildings, military projects, high rise and educational facilities.
The Legionella water management plan plan shall include written disinfection procedures for:
Disinfection shall be accomplished by the methods of Section 220.127.116.11.1 and/or 18.104.22.168.2.
At the time of cooling tower installation (either in a new system or as a replacement in an existing system), drawings shall be reviewed and siting issues addressed prior to beginning construction. The Legionella water management plan shall identify and address potential hazards related to any:
The Legionella water management plan shall include a written maintenance program that:
For new construction or for significant modifications to a potable water system, drawings shall be reviewed to identify and address issues prior to beginning construction. The Legionella water management plan shall address potential hazards from:
The Legionella water management plan shall include procedures for:
The Legionella water management plan shall meet the following requirements regarding startup and shutdown procedures. The Legionella water management plan shall include written procedures for: