Why Businesses Should Flush Water Pipes Before Allowing Employees To Return

Apr 29, 2020

As parts of the Tri-State begin to reopen in the coming days and weeks, the Northern Kentucky Water District and Greater Cincinnati Water Works are issuing a word of caution: Buildings closed for more than a week should flush their pipes before people return.

GCWW Superintendent of Water Quality Jeff Swertfeger says disinfectant added to the water may have dissipated. Stagnant water without disinfectant could lead to bacterial growth.

"Legionella is one type of bacteria that may be able to grow under those conditions," says Swertfeger. Legionella is the bacteria that can cause the potentially deadly Legionnaires' disease, a severe form of pneumonia.

Flushing involves letting water run for a period of time to clear out the old water and any bacteria, and to replace it with a fresh supply of water containing disinfectant.

Swertfeger says building managers should have a water management plan, so while it's an important concern and precautions should be taken, people shouldn't panic about the water supply.

"If you have even parts of your building that may be unoccupied for an extended period of time, it's probably a good idea to go in there and do that kind of flushing and get that water moving before that wing of the building is occupied again."

Both cold and hot water lines should be flushed. Water Works estimates it will cost about $3.50 for a home or small businesses to flush for 30 minutes.

Instructions From Greater Cincinnati Water Works:

1. Make sure all faucets in the building flow to a drain. If there are any water filters in the home, remove or bypass them.

2. Remove aerators and screens from every faucet.

3. Using the cold-water handles, turn on all faucets – including kitchen and bathroom sinks, utility and mop sinks, bathtub and shower, etc. - and allow them to run during the entirety of the flushing process.

  • Start with the lowest floor of the home. If the home has a basement, start there.
  • Move to the next highest floor and turn on all faucets.
  • Continue until all faucets are turned on in the home or building.

4. At the end of this process, water should be flowing from all the faucets in the building at the same time.

5. Let water run until the water is clear and the temperature has stopped changing at the last faucet
turned on. If you do not have a thermometer, flush for at least 30 minutes. Larger homes may need to
flush for a longer time.

6. Turn off the first faucet you turned on (lowest floor) and continue turning off faucets in the order they were turned on.

7. Repeat steps 3-5 using the hot-water taps.

8. Clean and reattach aerators to the faucets.

9. Flush, or run a cycle of, any appliance (ice maker, dishwasher, coffeemaker, laundry, etc.) for 10 minutes each.

10. Replace any filters and return equipment to service, if applicable.

More guidance from the Centers for Disease Control and Prevention is available here.