News Details

Water Quality and Service Events

No Unplanned Disruptions at this time. 

May 16--20:  Water Main Break on Alma near El Carmelo.  The coupling at a joint on a 12" concrete water main cracked Thursday evening, resulting in 38 customers losing water service.  Utilities crews worked through the night and restored water service by  6am.  Repair to excavated hole on Alma completed by Monday. 

May 15-31: Water quality at the San Francisco Hetch-Hetchy System's Irvington Portal may be variable. SFPUC will be starting up the new treatment systems at the newly expanded SVWTP over this time and as with any new facilities start up,there may be some temporary issues that impact water quality for short periods. Please call us at (650) 496-6967 if you have questions.

 
To stay abreast of breaking news about any water disruptions or quality issues, follow us on Twitter:@
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        • To report a leak, break or other emergency, call (650) 329-2579 
        • The most recent City Water Quality Annual Report is available here.
        • To view the slide presentation from the SFPUC on their water supply project status, click here
        • Have you heard about backflow prevention surveys we are sending out?  Get the full scoop about what is going on and why here. 
        • Special 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.

        Other water supply info & updates

        Chromium 6 Issue in News Not a Concern in Palo Alto---You may have heard stories in the news media about water safety and the potential for Chromium 6 exposure. First, we want to let you know that your water is safe. The water supplies that 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 being proposed for Chromium 6 that is expected to be finalized in July 2014. We will continue to ensure that all water supplies are safe and of high quality for you to drink.

        • Chromium is the 21st most abundant element in the Earth’s crust. The most common forms of chromium in the environment are trivalent, hexavalent, and the metal form. Chromium is found naturally in rocks, plants, soil and volcanic dust, humans and animals. The most common forms of chromium in the environment are trivalent, hexavalent, and the metal form. Hexavalent chromium is widely found in waters, including source waters for drinking water, at concentrations, typically at very low levels.
        • At the extremely low levels found in most drinking water, including our supply, there is no concern about safety. A larger concern for most people is when Chromium is airborne and can be breathed in when used in steel making, metal plating and leather tanning, or when using corrosion inhibitors, paints, dyes and wood preservatives. If you use work in these industries or use these products at home, please follow all packaging instructions when working with these materials.
        • Where should I go for more information?

         

        Algae levels were up last summer---The SFPUC focused operational resources on identifying the cause and appropriate mitigation for this algae event. As of October 2012, wholesale customer reports of algae issues decreased. On January 14, 2013 SFPUC  reduced chloramine target to 2.3 mg/L as nitrification was no longer a concern.

        • Long-term Actions: The SFPUC is developing an early warning monitoring program to better identify any future events, working on a plan and contractual vehicle to mechanically harvest plant-like algae by mid-2013, and exploring other improvements.
        • Click here for a reference map of the SFPUC Hetch-Hetchy System.
        • Water Quality Notice --in May 2012, during routine water sample testing, coliform bacteria in excess of the State standards were detected.  At no time was there any health emergency and the situation is resolved.  As required by State law, a notice was mailed to everyone in Palo Alto. A copy of that full public notice is here.

        SFPUC Hetch-Hetchy System operation changes

        •  

        • Source water blend change effective February 25: The Hetch Hetchy supply was increased to 155 mgd on February 25th.  The Sunol Valley Water Treatment Plant (SVWTP) rate will be decreased to about 40 mgd. The Harry Tracy Water Treatment Plant (HTWTP) remains shut down till end of April.

          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. 

          Parameter

          As of 2-21-13

          As of 2-25-13

          HH Flow (MGD)

          90

          155

          SVWTP Flow (MGD)

          95

          40

          Total Chlorine Residual (mg/L)

          2.3

          2.3

          Free Ammonia-N (mg/L)

          0.05

          0.05

          pH

          9.1

          9.1

          Turbidity (NTU)

          0.2

          0.2

          Conductivity (uS/cm)

          214

          106

          Hardness (mg/L)

          67

          33

          Alkalinity (mg/L)

          68

          32

          TOC (mg/L)

          2.0

          1.6

          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.

        Posted May 17, 2013