Innovative Water Consulting
Innovative Water Consulting
Mar 23, 2020 4 min read

Safely Managing Your Building Water System After the COVID-19 Shutdown

With mandated building closures across the United States due to Covid-19, Innovative Water Consulting, would like to remind building owners, facility managers, and building engineers of a probable danger when buildings reopen to the public. Legionella and other waterborne bacteria such as pseudomonas and mycobacterium grow and multiply rapidly when water is stagnant or slow moving.  The closure of buildings will lead to water that remains in pipes and is unused for weeks, leading to an overabundance of bacterial growth.  Taking the time to prepare in advance will mitigate the risks associated with an overgrowth of bacteria that will happen when potable water systems are back up and running.  


Before buildings owners and managers reopen their facilities to the public, they must execute a complete startup or re-commissioning of the potable (cold and hot) water systems.  This process is outlined in section 8 of ASHRAE 188-2018. 


SECTION 8.4 Commissioning. Instructions for commissioning of all building water systems shall be provided to the building owner or designee. Commissioning shall include the following:


  1. a. Procedures for flushing and disinfection

    1. 1.Procedures shall meet the requirements of AWWA C651 or AWWA C652 or comply with all applicable national, regional, and local regulations.

    3. 2. Disinfection and flushing shall be completed within three weeks prior to whole or partial beneficial occupancy.

      1. i. If beneficial occupancy of any part of the building is delayed more than two weeks but less than four weeks after disinfection, flushing of all fixtures shall again be completed.

      1. ii. If beneficial occupancy of any part of the building is delayed four weeks or more after disinfection, the need for disinfection, flushing, or both disinfection and flushing of unoccupied areas shall be determined by the Program Team.

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Building owners and managers must also flush and disinfect their entire potable water system to insure preventative measures are taken to combat all waterborne bacteria such as Legionella pneumophilia. This process is outlined in section 7 of ASHRAE 188-2018.


SECTION 7.1 Potable Water SystemsThis section describes the preventive measures required for potable water systems. The Program documents shall include identification of the responsible persons for every step of each Program requirement.


7.1.1 System Start-Up and Shutdown. The Program documents shall include procedures for

  1. b. shutdown, including any draining, purging, cleaning treatment, and control settings;
  1. d. restarting from a drained shutdown condition and from an undrained shutdown condition;
  3. e. monitoring and treatment following water supply interruptions or breaks in water supply piping;


7.1.2 System Maintenance. The Program documents shall include procedures for

  1. a. inspection of, and inspection schedule for, water-containing vessels and system components;
  3. b. flushing or mixing of stagnant or low-flow areas;


7.1.3 Water Treatment. The Program documents shall include

  1. c. procedures to address water supply interruptions or breaks in water supply piping;

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            After properly treating your plumbing following this shut down, you may still want to test your water before allowing customers, employees and visitors back into your facility.  After going through this tumultuous time of shutting down during COVID-19, the last thing you want to have is an outbreak of Legionella or another waterborne bacterium. 


            If you have any questions on how to keep your facility plumbing system safe after this shut down, do not hesitate to contact Innovative Water Consulting: Legionella & Water Treatment Solutions.  We provide expert help and advice on getting your building water system back up and running in the safest way possible.


Contact IWC HERE, or 1-877-492-7526 or