HomeMy WebLinkAbout2001-02-20 City Council (20)City of Palo Alto
City Manager’s Report
TO:HONORABLE CITY COUNCIL
FROM:CITY MANAGER DEPARTMENT: UTILITIES
DATE:FEBRUARY 20, 2001 CMR:146:01
SUBJECT:2001 PALO ALTO WATER MAIN DISTRIBUTION FLUSHING
PROGRAM - STATUS REPORT
This is an information report and no Council action is required.
DISCUSSION
Historically, the City of Palo Alto and approximately 85 percent of water utilities in the
United States use main flushing to improve water quality for water customers. Water utilities
may flush distribution mains for a variety of reasons: c’orrosion control, sediment removal,
taste and odor control, control of color, high turbidity, low chlorine residuals, bacteriological
growths, or as a response to customer complaints. The main objectives of Palo Alto’s
flushing program are to improve water quality, control bacterial growth and remove
sediment.
Between 1990 and 1993 calendar years, the Palo Alto Water Utility did not perform an
annual main flushing program because of the drought. During this period, customer water
consumption was also reduced, thereby accelerating sediment buildup in the mains. During
1992, numerous calls were received complaining about water quality. At that time, staff took
water samples in response to these calls and found that the reduced water quality was due to
the buildup of sediment in the mains. Also, City Fire Department personnel found more
sediment in their equipment from the City’s water system during 1992.
In 1993, the City resumed its annual water main flushing program. The water utility has not
received water quality complaints due to sediment build up in the distribution mains because
CMR: 146:01 Page 1 of 2
of the success of the annual distribution system-flushing program. This year’s water main
flushing will begin March 12, 2001 and continue through March 18, 2001. During this
period, the City’s Water Utility Operations Section will open fire hydrants to flush out
sediment that has collected in the mains during the past year.
The amount of water released during system flushing does not pose a threat of flooding.
However if a threat of flooding due to inclement weather should occur during the flushing
schedule, the flushing operation will be suspended until further notice. The water system
main flushing map and schedule will be mailed to the City’s water customers through utility
billings and displayed in the Palo Alto Weekly, Palo Alto Daily, City Internet Home Page,
and on the AT&T Broad Band Services community access channel.
ATTACHMENTS
A: ~2000 Water System Flushing Schedule and Map
PREPARED BY:Doug De Vries, Charles Borg,
Roger Cwiak, Scott Bradshaw
DEPARTMENT HEAD:
CITY MANAGER APPROVAL:
AUDREY SEYN~OUR o --
Assistant to the City Manager
CMR: 146:01 Page 2 of 2