Reopening? Flush Water Pipes

Don’t forget to flush the water pipes.

When your building goes unused, the water in your pipes may become stagnant.  Before you reopen, be sure to flush the water that has been sitting in your pipes and replace it with fresh water from the utility system.

Flush the Cold Water

  1. Remove and clean the filters, screens, and aerators from all faucets.
  2. Turn on the cold water fully for every faucet in the facility.  Start on the lowest floor, then move to the next highest floor, etc.
  3. All cold water outlets should be flowing at the same time during flushing.
  4. Flush toilets and urinals two or three times each.  Don’t forget to flush kitchen sprays and drinking fountains too.
  5. Empty the ice from all ice makers, then make and discard two additional batches.
  6. After at least 30 minutes (longer for bigger buildings), turn off faucets and outlets in the same order you opened them.

Flush the Hot Water

  1. Turn on the hot water and open all the faucets and outlets, the same way you opened the cold water faucets and outlets.
  2. Run the hot water for 45 minutes to ensure that the water in the water heater is flushed out.
  3. Close the faucets and outlets in the same order that you opened them.
  4. Note Water heaters should be set to at least 120 degrees to prevent microorganisms from growing.

Here is a printable flyer detailing the information listed on the page.

Reopening_FlushWaterPipes flyer detailing the information of this web page

Additional Resources provided by Maryland Department of the Environment

Building Flushing Guidance:

1.  Purdue University Center for Plumbing Safety, Flushing plans

https://engineering.purdue.edu/PlumbingSafety/resources/flushing-plans 

2.  Environmental Science, Policy, and Research Institute, Flushing guidance

https://esprinstitute.org/wp-content/uploads/2020/04/FINAL_Coronavirus-Building-Flushing-Guidance-20200403-rev-1.pdf 

Reducing risk to staff who are performing flushing

https://esprinstitute.org/wp-content/uploads/2020/05/FINAL_Reducing-Risk-to-Staff-Flushing-Buildings-20200501.pdf

Other Resources:

1.  The United States Centers for Disease Control (CDC) Guidance for Reopening Buildings After Prolonged Shutdown or Reduced Operation

https://www.cdc.gov/coronavirus/2019-ncov/php/building-water-system.html   

2.  Association of State Drinking Water Administrators (ASDWA) COVID-19 Resources for Building Water Systems

https://www.asdwa.org/2020/04/13/covid-19-resources-for-building-water-systems/ 

3.  The Maryland Department of the Environment (MDE) Water Supply Program COVID-19 Public Water System Compliance Challenges and Helpful Links

https://mde.maryland.gov/programs/Water/water_supply/Pages/WhatsNew.aspx 

4. EPA Water Utility Resources for the COVID-19 Pandemic

https://www.epa.gov/coronavirus/water-utility-resources-covid-19-pandemic