FEB. 24, 2021—As businesses and institutions re-open to employees and customers, owners and caretakers are reminded to flush water lines as part of the re-opening process. Buildings that have been unused for extended periods are likely to have old, stagnant water trapped in the plumbing, and this water should be flushed out so fresh water from the main can take its place.

Stagnant water can sometimes be discolored and have a bad smell or taste.  In rare instances, harmful microbes can grow in unused plumbing as chlorine from the municipal water treatment system declines in potency.  To prepare plumbing for re-opening:

  1. Check with facility staff or a property manager for any flushing plans already in place. Large and more complex buildings and facilities require more attention and planning in how the building is flushed and may already have a water management plan that should be followed.   Links are provided below for more information on flushing complex facilities, or you can contact a plumber for assistance.
  2. Disconnect any point-of-entry filters for the building and point-of-use filters on faucets. Remove and clean faucet aerators.
  3. Turn on the cold-water faucet closest to where the water enters the building, then all other cold-water faucets in the kitchen, utility rooms and bathrooms. Let the water flow for twenty minutes.
  4. Inspect, clean and flush all appliances that use water, including humidifiers, ice machines (dump at least two batches of ice), and dishwashers. Flush all toilets, spas and water features like fountains.  Finally, flush any outside spigots for 10 minutes.
  5. After flushing, turn off all faucets and replace all filters following the manufacturer’s instructions. Reconnect point-of-entry or other filter systems.

For more information:

CDC Guidance for Building Water Systems
CDC Toolkit to develop a building Water Management Plan
Building Water Quality and Coronavirus