Water Treatment

Water Treatment

Skip Navigation LinksHome » Departments » Water Treatment
​​​​​​​​​​Water Quality Information 

COVID19 Information​ ​ ​

City of Ann Arbor water system staff are focused on continuing to deliver safe water to our customers for c​onsumption and important daily hygiene. During this unprecedented public health crisis, critical services will continue such as drinking water, waste water, police, fire, emergency operations and waste and recycling pickup.​

Is Ann Arbor's drinking water safe?
Yes. The City of Ann Arbor disinfects drinking water prior to delivery to customers. We utilize multiple steps in our treatment process that physically remove and chemically inactivate viruses and bacteria, including the virus that causes COVID-19. The U.S. Environmental Protection Agency (EPA) recommends that Americans continue to use and drink tap water as usual. The city continuously monitors and tests our water throughout the treatment process and distribution system to ensure its quality and safety. 

Do I need to purchase bottled water?
No. The City of Ann Arbor will continue to deliver safe drinking water to your tap 24/7/365.

What can I do to help prevent the spread of the coronavirus?
Handwashing using tap water is critical to preventing the spread of COVID-19. CDC and other health organizations recommend frequent handwashing for at least 20 seconds each time. Up-to-date information is available via the EPA​.

Can the COVID-19 virus spread through drinking water systems? 
The World Health Organization has indicated that the “presence of the COVID-19 virus has not been detected in drinking-water supplies and based on current evidence the risk to water supplies is low."

Important Information for Businesses or Homes Temporarily Unoccupied due to COVID-19

The City of Ann Arbor uses chloramines to disinfect the water, which is a long lasting and effective disinfectant. However, when water sits stagnant in homes or buildings that are vacant or under occupied, water quality may become a concern. As homes and buildings are reoccupied, the city recommends the following best practices:

​Homes or Residential Buildings 

  1. Home flushing: Remove aerators from all faucets. Bypass heaters, softeners, filters or any other treatment devices if possible. Starting at the lowest faucet in the home, turn on all cold water taps, including tubs and showers. Leave all faucets on for at least 30 minutes. Turn off faucets in the same order in which they were turned on. Clean and re-install aerators.
  2. Hot water heaters and hot water plumbing: After home flushing is complete, flush the hot water heater.  Flush the hot water heater by opening the drain valve and flushing via a hose to a floor drain or sink for 30 minutes. If the drain valve is not functional or if there is a concern about it not reclosing after it is opened, run hot water at the nearest fixture to the hot water heater for 30 minutes. After flushing the hot water heater, turn on all hot water taps for 10 minutes to flush hot water system plumbing.
  3. Other water collection sites: Before using, clean decorative water features, as well as ice makers, water coolers, and other appliances that store water with a bleach solution. 

Businesses or Commercial Buildings

  1. Building flushing: Run water at all points of use, starting from closest to the water meter and moving to the furthest point from the meter. Flush cold water first at all fixtures within the building and then hot water at all fixtures, until all pipes have fresh water and hot water reaches maximum temperature. At least half an hour at each point is recommended. The CDC suggests wearing a mask and gloves while flushing. Until buildings are fully occupied, weekly building flushing is recommended.
  2. Hot water heaters: Follow manufacturer's instructions on hot water heater maintenance after a period of disuse and ensure water heaters are set to 120°F or higher.
  3. Other water collection sites: Before using, clean decorative water features, as well as ice makers, water coolers, and other appliances that store water, with a bleach solution. Filters in drinking fountains or other devices may need to be replaced.

For more guidance, information is available via the State of Michigan,  the EPA and the CDC .  

Keeping Our Customers Informed: PFAS

Keeping Our Customers Informed: Dioxane 

Fire Hydrant Flushing

The City of Ann Arbor conducts annual fire hydrant flushing beginning every spring and continuing on a weekly basis through the fall.​​​

Hydrant flushing is part of the City's annual maintenance and done to remove minerals and ​sediment that accumulate in the water lines over the course of a year. This preventative maintenance also allows us to check and record water pressure to ensure the water system is functioning properly. On occasion, the water in your home or businesses may have an orange or rusty appearance. The water is safe to use and drink, but it can cause stains to laundry if the discoloration is not first cleared from the lines. If this occurs, products like “Rover" can help remove temporary laundry coloration. The water discoloration is being caused by iron sediment in the water main being disturbed by the hydrant flushing. If this occurs, please run your COLD water for several minutes and flush your toilet to clear your lines. Please do not run hot or warm water, as this forces the discolored water into the water heater, mixing it with clear stored water. If you do get rusty water in your hot water tank, it is necessary to drain the hot water tank per the manufacturer's instructions.

To view the areas currently hydrant flushing, as well as those on the schedule to flush next, see the Hydrant-flushing map. 

​​​Subscribe for water quality-related updatesSubscribe for water quality-related updates.​

Brian Steglitz,
Water Treatment Services Manager

919 Sunset Road
Ann Arbor, MI 48103
Phone: 734.794.6426​
Email: [email protected]

Business Hours: M-F 8 a.m.-5 p.m. (except city holidays)​

Open 24 hours a day, seven days a week for water emergencies: 734.994.2840