View SFPUC slide presentation on their water supply project status, here
Backflow prevention surveys--get the full scoop about what is going on and why here.
NOTE to 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.
Water Supply Updates
RIM FIRE---The Rim Fire reached the shores of the Hetch-Hetchy Reservoir, part of the system from which Palo Alto receives all of its water, but there has beens 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. It bears repeating that there is no concern about a drinking water shortage! However, the water from Hetch Hetchy reservoir is so pristine and high quality, it is not filtered. This means that if at some point inthe future ash from the fire causes the water’s turbidity to exceed certain threshold limits, the SFPUC will need to switch to using its local reservoirs.
Using their two local treatment plants, Sunol and Harry Tracy, along with added supplies from agreements with other water districts, the SFPUC can meet local demands for 4-5 months at this time of year.
In the event the SFPUC switches to local supplies, the water quality will be similar to what we experience during the annual Hetch Hetchy winter maintenance shutdowns.
Chromium 6 Issue Not a Concern in Palo Alto---The water supplies we receive from the San Francisco Public Utilities Commission (SFPUC) exceed all safety requirements for drinking water. Our water supply complies fully with the new California Chromium 6 MCL standard expected to be finalized in July 2014. Click here for the latest SFPUC report on Chromium 6.
Chromium is an abundant element in the Earth’s crust. Chromium is 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.
At the extremely low levels found in most drinking water, including our supply, there is no concern about safety. Where should I go for more information?
Algae---Long-term Actions: The SFPUC is developing an early warning monitoring program to better identify any future algae bloom events, working on a plan and contractual vehicle to mechanically harvest plant-like algae by late 2013, and exploring other improvements.
SFPUC Hetch-Hetchy System Operations
Click here for a reference map of the SFPUC Hetch-Hetchy System.
Source water blend change (effective November 4, 2013)
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.
As of 11-5-13
As of 11-12-13
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.
Read how Hetch-Hetchy's system uses gravity not electricity to deliver your water here.
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.