Water treatment, Sanitizing, & Management System

water syterm plan

Section 8.1 - Potable Water Systems

8.1.1 New Construction/Renovation.

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:
  • possible cross connections between potable and non-potable water
  • inadequate access to equipment with water storage capacity such as water expansion tanks, water hammer arrestors and water heaters
  • dead legs or low flow portions of the piping system
  • stratification in hot or cold water storage tanks and heaters
  • heat transfer from hot or cold water piping or heat rejection equipment resulting in heat gain in cold water piping or heat loss in hot water piping
  • 8.1.2 New Systems, Startup and Shutdown.

    The Legionella water management plan shall include procedures for:
  • cleaning and disinfection before commissioning any new system
  • shutdown, including any draining, purging, cleaning treatment and control settings
  • any unplanned loss of operating energy, loss of water treatment chemicals or system component repair or replacement
  • restarting safely from a drained shutdown condition or from an undrained (stagnant) shutdown condition
  • monitoring and treatments following water supply interruptions or breaks in water supply piping
  • the method and frequency of temperature measurements in the water heater and in the distribution system Identification of the responsible persons for these activities shall be documented.
  • 8.1.3 System Maintenance.

    The Legionella water management plan shall include:
  • inspection frequencies for water containing vessels and system components
  • maintenance procedures based on equipment manufacturers’ recommendations for
  • 1) cleaning, disinfection and/or replacement of system components
    2) flushing or mixing of stagnant or low flow areas
    ) other treatments and any required monitoring that the Legionella water management plan team decides are necessary for
    i. hot and cold storage tanks
    ii. ice machines
    iii. water hammer arrestors
    iv. expansion tanks
    v. water filters
    vi. shower heads and hoses
    vii. electronic faucets
    viii. aerator and/or faucet flow restrictors
    ix. non-steam, aerosol generating humidifiers
    x. water heaters with any stored volume of water
  • c) inspection notes and a corrective actions log
  • d) regular updates of system component operating manuals
  • e) identification of the responsible persons.
  • 8.1.4 Water Treatment.

    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.
  • monitoring method and frequency of chlorine residual measurement in the hot and cold water system. Note: The chlorine concentration recommendation for Legionella control is >0.5 ppm (mg/l) free residual oxidant, as chlorine. If the Legionella water management team finds that this recommended concentration is not achieved, then it may determine that supplemental treatments are required.
  • inspection and maintenance schedule for all water treatment equipment and chemicals, which shall be EPA-registered and labeled for potable water disinfection; all treatments shall be applied in compliance with local, state and federal regulations
  • schedule for any monitoring required as part of the water treatment plan
  • procedures following water supply interruptions or breaks in water supply piping
  • identification of responsible persons for maintaining equipment and chemicals
  • 8.1.5 Emergency Disinfection.

    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 thermal shock (see Section 8.1.5.1.1) and chemical disinfection (see Section 8.1.5.1.2 or 8.1.5.2) 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.

    8.1.5.1 Hot Water Systems.

    Disinfection shall be accomplished by the methods of Section 8.1.5.1.1 and/or 8.1.5.1.2.

    8.1.5.1.1

    An effective method for emergency disinfection of contaminated hot water systems is thermal shock treatment to be implemented using the following procedure:

  • local building and sanitary codes shall be used to set temperature limits
  • building occupants and facility personnel shall be informed that disinfection with water temperatures that could cause scalding will be used
  • water temperatures shall be maintained at 71-77°C (160-170°F) while progressively flushing each outlet in the system
  • a flush time of thirty minutes shall be attempted. The intent is to provide thermal eradication for as long as possible up to thirty minutes; the outlet flow rate shall not surpass the capacity of water heaters to maintain temperature. Note: In healthcare facilities, flushing should be performed in a manner that reduces the risk of scalding and aerosolization of potable water in patient-care areas. This can be accomplished by flushing to waste upstream of outlets, by flushing risers and recirculation loops from outlets not used by or near patients, or by flushing outlets in patient rooms at low flow or with aerators removed.
  • 8.1.5.1.2

    An effective method for emergency disinfection of contaminated hot water systems is shock halogenation to be implemented using the following procedure:

  • building occupants and facility personnel shall be informed that halogen disinfection with concentrations exceeding EPA allowable limits for drinking water will be used
  • an EPA-registered and labeled drinking water product shall be added in accordance with use directions for the EPA-labeled product
  • all outlets shall be flushed until halogen concentration at representative distal taps and faucets is confirmed by measurement and documented
  • close all outlets and disinfect with halogen for a minimum of 2 hours (not to exceed 24 hours).
  • thoroughly flush all outlets. Measure halogen concentration at representative outlets to confirm it is within EPA limits before reuse of the system. Example: One EPA approved halogen is chlorine. If using chlorine for disinfection, the level of free residual chlorine should be raised to 20-50 mg/L (ppm) of free residual oxidant, as chlorine and maintained at approximately 50 mg/L (ppm) for one hour or at approximately 20 mg/L (ppm) for two hours. The pH of the water should be maintained below pH 8.0 to prevent significant reduction of disinfection efficacy. (Note: If chlorine dioxide is used, pH control is not required)
  • 8.1.5.2 Cold Water Systems.

    Emergency disinfection of the cold water potable water system shall be achieved by the following halogenation procedure:

  • building occupants and facility personnel shall be informed that halogen disinfection with concentrations exceeding EPA allowable limits for drinking water will be used in the procedure
  • an EPA-registered and labeled drinking water product shall be added to the hot water system in accordance with use directions for the EPA-labeled product
  • all outlets shall be flushed until halogen concentration at representative distal taps and faucets is confirmed by measurement and documented
  • close all outlets and disinfect with halogen for a minimum of 2 hours (not to exceed 24 hours)
  • thoroughly flush all outlets. Measure halogen concentration at representative outlets to confirm it is within EPA limits before reuse of the system.
  • Example: One EPA approved halogen is chlorine. If using chlorine for disinfection, the level of free residual chlorine should be raised to 20-50 mg/L (ppm) of free residual oxidant, as chlorine and maintained at approximately 50 mg/L (ppm) for one hour or at approximately 20 mg/L (ppm) for two hours. The pH of the water should be maintained below pH 8.0 to prevent significant reduction of disinfection efficacy. (Note: If chlorine dioxide is used, pH control is not required)

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    Section 8.2 - Cooling Towers and Evaporative Condensers

    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.

    8.2.1 Equipment Siting.

    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:

  • equipment siting issues that allow contamination from building systems or facility processes to be drawn into the equipment
  • equipment siting issues that allow cooling tower or evaporative condenser exhaust to infiltrate buildings
  • equipment access issues that inhibit maintenance and inspection activities.
  • 8.2.2 New System Startup.

    The Legionella water management plan shall include a written startup plan that includes:

  • any cleaning steps that are part of commissioning of the cooling system, with responsible persons identified
  • a means of ensuring that an ongoing water treatment program is initiated immediately once the system is charged with water.
  • 8.2.3 System Maintenance.

    The Legionella water management plan shall include a written maintenance program that:

  • specifies the frequency of inspections for general system cleanliness, drift eliminator condition, condition of fill material, and water distribution system operation
  • includes basin or remote sump cleaning and purging of stagnant or low flow zones
  • identifies responsible persons and includes a mechanism for recording maintenance activities and inspection notes.
  • 8.2.4 Water Treatment.

    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:

  • specify all equipment and chemicals used for the purpose of treating the open recirculating loop
  • require that control of solids in cooling tower water and in basins be achieved through filtration, physical cleaning, or other means such as chemical water treatment
  • Note: Contaminants in a cooling tower system, both suspended and precipitated solids, facilitate the growth of bacteria and biofilms that can increase the potential for Legionella.
  • include a schedule for required inspection, maintenance, monitoring and a corrective actions log
  • identify the persons responsible for providing and maintaining the system water treatment
  • 8.2.5 Shutdown and Startup.

    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:

  • shutdown that includes all chemical pretreatment steps or pump cycling protocols, as well as provision for system drainage for shutdown periods of longer duration, as specified in the plan
  • startup from a drained system
  • startup from an undrained (stagnant) system that exceeds the number of idle days specified in the plan.
  • Each of these shutdown and startup procedures shall identify the persons responsible for initiating and executing the procedure.

    8.2.6 Disinfection of Cooling Towers and Evaporative Condensers.

    The Legionella water management plan plan shall include written disinfection procedures for:

  • remedial on-line disinfection which includes the conditions that would prompt its application and identifies the persons responsible for initiating and executing the procedure
  • emergency disinfection which includes the conditions that would prompt its application and identifies the persons responsible for initiating and executing the procedure.
  • 8.2.7 Location of Cooling Tower Make-up Valve.

  • The height of the discharge outlet of the cooling tower make-up valve over the maximum water level in the cooling tower or evaporative condenser basin must comply with state and local codes, but in no case shall be less than 4 inches (10.2 cm).
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    Section 8.3 - Whirlpool Spas

    This section describes requirements for public whirlpool spas.

    8.3.1 General.

    Public whirlpool spas shall be operated according to the state and local codes that relate to public swimming and spas.3 If none apply, then the public whirlpool spas shall be operated according to the voluntary consensus standard APSP 11, Standard for Water Quality in Public Pools and Spas.

    Note: These codes and standards typically cover mechanical specifications, operational parameters, water chemistry, and microbiology. While specifically targeted to fixed spas, the operational principles are also applicable to public portable spas.

    8.3.2 Bather-Related Requirements. The Legionella water management planP plan shall include the following requirements relating to bathers:

  • a written determination of the allowable bather load for each whirlpool spa
  • a written policy to ensure that the allowable bather load for each whirlpool spa is clearly posted and enforced.
  • a written policy to ensure that there is a clear posting of the increased health risk related to use of whirlpool spas by individuals who are immunocompromised or who have chronic lung disease.
  • 8.3.3 Filter Operation and Maintenance.

    The Legionella water management plan plan shall include a written policy for adequate filtration of the whirlpool spa water.

    Note: Filtration of the whirlpool spa water is essential for adequate water quality.

    8.3.3.1 Cartridge (canister) Filters.

    The Legionella water management plan plan shall include a written policy for the inspection and replacement schedule for all cartridge-type filters and related equipment, including pressure gauges and valves.

    8.3.3.2 Granular Filters.

    The Legionella water management plan plan shall include a written policy for the backwashing criteria and schedule and for the routine inspection, replacement procedures, and schedule for all granular-type filters and related equipment, including pressure gauges and valves.

    8.3.4 Water Quality and Disinfection.

    The Legionella water management plan plan shall include a written description of the procedures for maintaining adequate water quality and disinfection. Note: The maintenance of continuous disinfection in whirlpool spas is critical for control of infectious agents (including Legionella) in spa water. These disinfection and water changing procedures are generally well described in most state and local regulations relating to public swimming and bathing facilities and in APSP Standard 11 (see Item 4, References).

    The Legionella water management plan plan shall include the following:

  • schedule for changing the whirlpool spa water on a regular basis
  • policy for maintaining the pH of the water between 7.2 and 7.8
  • policy for maintaining free residual halogen levels, including either a free residue of chlorine of 3—8 mg/L (ppm), or a free residual bromine of 4—8 mg/L (ppm)
  • policy for shock disinfection of the whirlpool spa at the end of each day with at least a free residual of 10 mg/L (ppm) halogen, followed by circulation for at least 1 hr
  • policy for maintenance of the halogenation system in accordance with the manufacturer’s recommendations
  • measurement schedule and logbook of all residual halogen measurements
  • a corrective actions log
  • policy for requiring operational logbooks to retain at least the most recent 12 months.
  • 8.3.5 Microbiology.

    The microbiological standards to be achieved by public whirlpool spas are regulated by state and local health departments in order to control disease transmission, particularly fecal-oral transmission of disease. The Legionella water management plan plan shall have a written description of these operational procedures.

    8.3.5.1 Monitoring.

    The Legionella water management plan plan shall include the:

  • description of the scheduled (at least monthly) testing of the spa water for indicator organisms and pathogens of concern.
  • policy for maintaining the levels of indicator organisms at or below the standard threshold, including:
  • § the Total Heterotrophic Aerobic Bacteria colony count shall be ≤200 CFU/ml § the E. coli count shall be < 1 CFU/100 ml.

    Note: CFU = colony forming unit in standardized tests

  • description of the procedures to be followed if the results are unsatisfactory, including a review of the halogenation records and the repetition of the microbiological tests.
  • Note: The Legionella water management plan team makes the decision whether or not to test specifically for Legionella or other pathogens (e.g., Pseudomonas aeruginosa), the frequency of testing, the nature of the samples (water and/or biofilm), and the interpretation of the results. A description of this process can be found in informative Appendix B. Refer to Validation Summary and Monitoring Schedule in this appendix.

    8.3.5.2 When Contamination Is Discovered. The Legionella water management plan plan shall include a description of the procedures to be followed if there is evidence of gross contamination (e.g., feces, vomiting). The policy for addressing such incidents shall include taking the spa out of use immediately for cleaning and disinfection of the entire system.

    8.3.5.3 When Legionellosis Cases Are Suspected. The Legionella water management plan plan shall include a description of the procedures to be followed if there are suspected legionellosis health problems associated with the use of a whirlpool spa. 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 (see 8.3.4d). These procedures shall include criteria for when to test for Legionella in the spa water.

    8.3.6 Operating Manuals. The Legionella water management plan plan shall include a policy for regularly updating all operating manuals for filters, pumps and halogenation equipment and maintaining them at a secure location that is accessible to maintenance personnel.

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    Section 8.4 - Decorative Fountains and Other Water Features

    This section describes Legionella water management plan plan requirements for decorative fountains and other water features that are associated with buildings.

    8.4.1 Equipment Sitting.

    The Legionella water management plan plan shall identify and address potential hazards due to:

  • organic contamination drawn into the system (for example from of kitchen exhaust fans, plants, truck bays, or other sources)
  • inadequate drains and stagnant areas
  • Note: Drains should be situated at the lowest level of the feature with no other local low points that are not served by drains. Stagnant areas or areas that cannot be cleaned should be eliminated.
  • Inadequate access to pump(s), filter(s), tanks and treatment equipment.
  • external heat sources and inadequate air flow
  • Note: If submerged lighting is used, the water circulation and evaporation rate should be such that the water temperatures in the area of the light and in the overall water feature are not significantly elevated from this external heat source. Whenever possible, LED lighting should be used in place of incandescent lights. If UV systems are used for disinfection, they should be sized for the flow volume because oversized UV units will add excess heat to the system.

    Note: Where possible, air flow should be towards the water feature and away from people. Small water features typically reject little to no heat. Larger water features, especially units with significant heat sources, may need additional air flow to remove generated heat and moisture.

    8.4.2 Operation.

    The Legionella water management plan plan shall include a written description of the procedures for operating water features such that they meet the following requirements:

  • if the water feature is not in operation for three or more consecutive days, it shall be drained, all components cleaned with a disinfectant, and refilled.
  • submerged lights shall not be operated without a circulating pump running.
  • a circulating pump shall be kept running to minimize stagnant conditions.
  • 8.4.3 Maintenance.

    The Legionella water management plan plan shall include a written description of the procedures for maintenance of water features to include the following:

  • fountains and other water features shall be cleaned regularly in order to reduce the nutrients available for Legionella growth. The basin of the unit shall be cleaned when buildup of dirt, organic matter, or other debris is visible.
  • pumps and filters shall be maintained as recommended by filter manufacturer.
  • Note: Issues with bearings or pressure drop from dirty filters can cause pumps to run hotter.
  • when filters are used, a microbial fouling treatment program shall be implemented to prevent bacterial growth on the filters.
  • 8.4.4 Water Treatment.

    Microbial fouling control is required for water features. The Legionella water management plan plan shall include a written description of water treatment procedures.

    For small systems less than 5 gallons (20 liters) total water volume:
  • weekly cleaning, disinfection of equipment and components, and replacement of water shall be required or
  • periodic use of an effective EPA-registered biocide applied according to instructions on the EPA-label.
  • For larger systems, an effective biocide program shall be required for fouling control. If biocides are used, they shall be registered by the EPA for this application and used in accordance with local and governmental regulations. Note: Further information and details on the use of biocides are given in ASHRAE Guideline 12 and the ASHRAE Handbook, Applications (see Appendix A, Bibliography).

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    Section 8.5 - Aerosol Generating Air Coolers, Humidifiers and Air Washers

    This section describes requirements for air coolers, humidifiers, and air washers that cool or humidify by generating small water droplets discharged into the air. It includes, but is not limited to:

    Air Washers. Air washers utilize high-pressure nozzles to reduce water to small droplets for efficient evaporation.

    Misters. Misters produce an aerosol by use of ultrasonic devices, spinning disks, or spray nozzles.

    Note: Heated element and vapor-type humidifiers convert water to vapor (not aerosols) that is discharged into the space being conditioned. Due to the elevated temperature and the fact that water droplets are not generated, the risk of Legionella transmission from these types of humidifiers may not be significant.

    Note: ASHRAE Guideline 12 provides informative guidance on design, maintenance, and operation of these types of equipment and systems (see Appendix A, Bibliography).

    8.5.1 Equipment Siting.

    For the types of aerosol-generating equipment identified in this section, the Legionella water management plan plan shall identify and address any deficiencies in:

  • equipment siting that allows contamination to be drawn into the system
  • equipment access that inhibits required maintenance and inspections.
  • 8.5.2 New System Startup.

    The Legionella water management plan plan shall include a written startup plan that includes any cleaning steps that are part of commissioning of evaporative air coolers, misters, humidifiers and air washers and identifies responsible persons.

    8.5.3 System Maintenance.

    For the types of aerosol-generating equipment identified in this section, the Legionella water management plan plan shall include (where applicable):

  • a written maintenance schedule that specifies inspections for general system cleanliness, air washer mist eliminator condition, condition of evaporative cooler/humidifier media, condition of any spray nozzles and water distribution system operation
  • basin or remote sump cleaning and purging of stagnant or low flow zones
  • documented maintenance procedures, inspection notes and corrective actions
  • identification of responsible persons
  • 8.5.4 Water Treatment.

    When water treatment is used in evaporative air coolers, misters, humidifiers or air washers, the Legionella water management plan plan shall include:

  • a written water treatment plan that specifies all equipment and chemicals used for the purpose of treating the open recirculating loop
  • an inspection and maintenance schedule for the water treatment equipment
  • a schedule for any monitoring required as part of the water treatment plan
  • identification of the persons responsible for providing and maintaining the system water treatment program
  • 8.5.5 System Shutdown and Start-Up.

    For the types of aerosol-generating equipment identified in this section, the Legionella water management plan plan shall include (where applicable) procedures for:

  • shutdown that includes any chemical pretreatment steps or pump cycling protocols, as well as provision for system drainage for shutdown periods of longer duration, as specified in the plan
  • startup from a drained system
  • startup from an undrained (stagnant) system that exceeds the number of idle days specified in the plan
  • identification of the persons responsible for initiating and executing each startup and shutdown procedure.
  • 8.5.6 Disinfection.

    For the types of aerosol-generating equipment identified in this section, the Legionella water management plan plan shall include written procedures for:

  • remedial on-line disinfection that specifies the conditions which would prompt its application and identifies the persons responsible for initiating and executing the procedure
  • emergency disinfection that specifies the conditions which would prompt its application and identifies the persons responsible for initiating and executing the procedure.
  • REFERENCES

  • Minimizing the Risk of Legionellosis Associated with Building Water Systems.
  • Code of Federal Regulations, 40 CFR 141-143.
  • Refer to the National Swimming Pool Foundation web site for applicable state and local codes. (http://www.nspf.org/Codes_Links.html).
  • ANSI/APSP 11-2009, Standard for Water Quality in Public Pools and Spas.
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