Flushing Guidance

After any extended period of closure there may be water-quality issues that emerge when you return, reopen your business and begin using water again.

On March 16, 2020 the City and County of San Francisco issued a Public Health Order requiring that residents stay home, with the only exception being for essential needs. This order resulted in the mandatory closure of many buildings and businesses in the City.

The closure of a building may result in significant reduction in water use throughout the building, that in turn may result in degradation in water quality. Water-borne bacteria may have grown in the stagnant water in your internal plumbing system.

Important Steps to Mitigate the Impacts of the Reduction in Water Use

1. Review the flushing guidance and checklist to assist you in preparing your water system to ensure that high-quality, safe and reliable water service can be restored.
2. After implementing these measures, it is recommended that you consult with a plumbing contractor or other health and safety contractor.
3. If, after completing the steps outlined, you experience any issues with your water, such as discoloration, odor or taste concerns, contact 3-1-1 for assistance.

From within San Francisco: 3-1-1 (for TTY, press 7) or (415) 701-2311

From outside San Francisco: (415) 701-2311 (for TTY, press 7) or TTY direct: (415) 701-2323

Questions

If you have any questions or need any additional information, please contact the SFPUC Water Quality Division at (650) 652-3100, Monday-Friday 8:00am-5:00pm.

References

• American Water Works Association (AWWA), April 2020 – Notice on returning homes to service
• AWWA Sept. 2020 - Responding to Stagnation in Buildings with Reduced or No Water Use
• ANSI/ASHRAE, 2019 - Standard 188-2018, Legionellosis: Risk Management for Building Water Systems
• Centers for Disease Control and Prevention – Safe Water Program
• Environmental Science, Policy & Research Institute (ESPRI), April 2020 – Building Water Quality and Coronavirus: Flushing Guidance for Periods of Low or No Use
• Water Research Foundation (WRF), May 2019 – Flushing Guidance for Premise Plumbing and Service Lines to Avoid or Address a Drinking Water Advisory
• Washington State Department of Health Drinking Water Guidelines - COVID-19