Questions or concerns about water quality? Call us at (650) 329-2161 to report issues or request information. Sometimes our water intake may change and come through a local storage reservoir rather than straight from Hetch Hetchy, which can stir up sediment. If you experience discoloration or sediment in water coming from your tap, flush the water for a minute or more until the water clears. There may be more oxygen in the water, which can give a cloudy appearance. This is not harmful to drink. If problems persist or seem different than these conditions, please notify us right away, take precautions, and do not drink the water.
SFPUC Water Supply project status (slide presentation) available here
Backflow prevention surveys--get the full scoop about what is going on and why here.
Highly Sensitive Customers---since occasional minor fluctuations in water quality do occur, people with high-sensitivity to water quality issues (e.g. those with compromised immune systems) should consult with their health care provider to determine in general if they should be taking precautionary measures such as adding filtration devices.
RIM FIRE---The Rim Fire had no operational or water quality impact to the SFPUC water system. The water system is being monitored very closely and should things change, the SFPUC has back-up plans ready to go.
Chromium is an abundant element in the Earth’s crust, found naturally in rocks, plants, soil and volcanic dust, humans and animals. One form, hexavalent chromium, is widely found in waters, including source waters for drinking water, typically at VERY low concentration levels.
ALGAE---Long-term Actions: The SFPUC is developing an early warning monitoring program to better identify any future algae bloom events and exploring other improvements.
SFPUC Hetch-Hetchy System Operations
Click here for a REFERENCE MAP of the SFPUC Hetch-Hetchy System.
Click here.to read about how the Hetch-Hetchy system uses gravity not electricity to deliver your water
Source water blend change (effective January 22, 2014)
Update: As of August 2014, you may notice that your tap water has a slight chlorinated taste during the next few months. At different times of the year and under different supply source conditions, the SFPCU uses different chloramine dosing at their treatment plants, resulting in different chloramine/chlorine levels within the distribution system. The number fluctuates both from season to season and from year to year. The key point is the 2.8ppm reported most recently is within health and safety regulations and this is a normal annual process. If you have any questions or concerns please contact our Water Operations at (650)496-6967.
The following table compares water quality parameters at Irvington Portal. This data is based on the most recent sampling results and represents an estimate of how the blend parameters will change.
Note: The Hetch Hetchy reservoir was shut down for maintenance between January 6-26, 2014 during which time local reservoirs have been used. When the Hetch-Hetchy supply is restored there will be variable water quality for a few days (1/23-1/26). See above for note re brief period of sediment in water east of El Camino.
As of 1-22-14 (East of El Camino variance in green)
As of 1-27-14
HH Flow (MGD)
SVWTP Flow (MGD)
Total Chlorine Residual (mg/L)
Free Ammonia-N (mg/L)
Please call the Water Quality Division at (650) 652-3100 (or through Millbrae Dispatch at (650) 872-5900) if you have any questions.
Planned Disruptions are no longer posted to respect the privacy of the impacted customers, all of whom receive direct notification of the disruption.
Why are any planned disruptions necessary? Currently the City is in the process of performing system and seismic upgrades, along with increasing the storage capacity for the City's water distribution system. This work may cause some customers to experience lower than normal water pressures during high demand times of the year, such as warmer months and high usage times of day. You may also experience some cloudy water due to valving modifications done to support the affected areas. There are two primary reasons for water quality changes and planned disruptions:
San Francisco Public Utility Commission (SFPUC)'s Routine Maintenance on the Hetch-Hetchy supply system. While most of the time we are getting our water supply straight from the Hetch-Hetchy aqueduct, periodically that aqueduct must be closed for maintenance and our supply is mixed with water from other reservoirs in the system. In those cases, the water is still high quality and meets all standards, but may be cloudy (due to air bubbles) or have a slightly different smell or taste.
The City's Ongoing Aggressive Maintenance Program to test ("exercise") and replace old water valves. An average of 100 valves per month are exercised and as many as 12 per month are replaced. Everyone benefits from these improvements to the water distribution system, and we thank our customers for any inconvenience they must experience while their water is briefly turned off. Customers always receive advance notice of these shut-offs.