HomeMy WebLinkAboutStaff Report 400-07City of Palo Alto
City Manager’s Report
TO:
FROM:
DATE:
SUBJECT:
HONORABLE CITY COUNCIL
CITY MANAGER
OCTOBER 29, 2007
DEPARTMENT: UTILITIES
CMR: 400:07
ELECTRIC RELIABILITY IMPROVEMENTS FOR CALIFORNIA
AVENUE AREA
This is an informational report and no Council action is required. This report discusses the recent
power outages in the California Avenue business district and staff’s plans to improve the
reliability of the electric system.
BACKGROUND
The California Ave business district (UnderNound District #22) was constructed in 1981. The
service life of an underground electric system is normally 30 years aaad staff proposed funds to
rebuild this district in 2010-11 in the 2006-07 Budget under Capital lanprovement Project (CIP)
EL-11005. In the 2007-08 Budget, this CIP was moved up to 2009-10 due to si~as of system
deterioration.
In 1996, Council adopted a resolution (CMR:182:96) that mandated the use of pad-mounted
electric equipment due to the reliability problems caused by subsurface electrical equipment. The
CMR had exceptions for areas where space limitations made it difficult to place pad-mounted
equipment. As part of the City’s cunent design process, staff endeavors to obtain above pound
equipment locations where possible. It continues to be a difficult task to obtain locations for the
required equipment because property o~vners/developers do not ~vish to have pad-mounted
equipment on their property. When pad-mounted locations ca~mot be obtained, diminished long-
term reliability of the electric system ca3~ be anticipated. This is the case along California
Avenue.
Beginning in February 2006, the California Avenue area began experiencing a serieS of outages.
These outages have been largely due to connector and equipment failures where surface water
and contaminants entered the system through ventilated vault covers and deNaded the electric
insulation. Vaults containing transformers must have ventilated covers so that heat can escape,
CMR:400:07 Page 1 of 3
and for this reason, cannot be sealed. Staff continues to find oils, grease, and cleaning agents in
electric vaults. On two occasions in the last year, Utilities Operations has had to pump out and
clear vaults of a combination of pease, cleaning solvents, food and other debris. This
combination of chemical agents reacts with the rubber and metals in the electrical equipment,
causing them to deteriorate at an accelerated rate. On another occasion, someone disposed of a
cigarette in a vault which ignited debris in the vault.
There are hundreds of electrical com~ectors located below pound which are exposed to these
conditions. This is one of the main causes of the failures now talcing place.
The utility has a visual and infi’ared heat detection inspection propam for components on the
California Avenue system. Visual inspections were completed in November 2004, June 2005,
April 2006, and September 2007 and the most recent infrared heat detection inspection was
completed between September 6t~’ and September 30th of this year. The September 2007 infi-ared
inspection found an overheated electric com~ector on the system and this defect was corrected.
Soon after the repair, the system failed at another point which had no indication of a problem
during the inspection. This outage was caused by insulation failure which is usually
undetectable prior its occurrence.
As a short-term response to the outages, the electrical system has been reconfigured to limit the
number of customers impacted by the outages. However, the only way to ensure a substantial
improvement in the reliability of the system is to redesiN~ and rebuild the primary electric
system in the area.
DISCUSSION
Staff has been working for the past year to find locations to install pad-mounted (above-pound)
electric, equipment. This requires negotiation with business and property owners along with the
City’s Plam~ing and Community Enviromnent Department. In addition, staff prepared a master
plan for the district’s electric system. Plans are nearly complete to rebuild the area bounded by
Sherman and Jacaranda Lane between Birch and 1~1 Camino. Construction will begin as soon as
construction materials can be procured. Additional plans are being prepared for the remaining
areas, and construction work will commence in early 2008.
It should be noted that system outages will be required to rebuild the system. These outages will
be scheduled so that they do not occur during the holiday shopping period and, where possible,
wilt occur outside business hours for area merchants. Staff will attend a meeting with the
California Avenue ~M’ea Development Association (CAADA) and will discuss outreach to the
merchants so that outages can be scheduled.
Staff will propose budge~ changes during the mid-year budget process to obtain the necessary
funding to complete this rebuilding effort. Staff will recommend that other projects in the Capital
hnprovement Program be postponed as a result.
CMR:400:07 Page 2 of 3
RESOURCE IMPACT
Funds are available in the Electric C~ (Electric System Enprovements EL-98003) to allow staff
to initiate work. A Budget Amendment Ordinance (BAO) at the mid-year budget cycle will
address funding the major portion of this work.
POLICY IMPLICATIONS
None at this time.
ENVIRONMENTAL REVIEW
This project is categorically exempt from environmental review under the Califonaia
Enviromnental Quality Act (CEQA), pursuant to sec. 15302 of the California Public Resources
Code, which provides an exemption for replacement or reconsm.lction of existing structures and
facilities located on the same site and having the same purpose as the structures replaced.
PREPARED BY:Sam Zuccaro, Electric Engineering Manager
Tomm Marshall, Asst. Director of Engineering
DEPARTMENT APPROVAL:
CITY MANAGER APPROVAL:
VALE ~I~/E ~. SONG
D~rector of U@lmes
EMILY H~SON
Assistant City Manager
CMR:400:07 Page 3 of 3