Palo Alto residents concerned about the risk of a gas-line explosion similar to the one that devastated a neighborhood in San Bruno Thursday should be reassured, City of Palo Alto Utilities officials said Friday morning.
Although PG&E owns and maintains natural-gas transmission lines under Middlefield and other major Palo Alto roads, the city's utilities staff will immediately call PG&E when there is a report of the smell of gas involving its system, Linda Clerkson, communications manager to the city manager, said.
That would occur when anyone calls the city utilities' emergency dispatch, or when the city's utilities staff conducts its annual leak survey.
The department runs ongoing and proactive safety programs that include leak detection surveys, pipeline upgrades and replacements, pipeline corrosion control, 24/7 customer response, and promotion of gas-safety awareness and education to residents and businesses in Palo Alto, according to city officials.
During 2009, the department completed its annual walking survey to check for leaks of all 19,311 gas service lines in the City. An annual mobile survey of all 205 miles of city gas main pipes was also conducted, according to Greg Scoby, Palo Alto's engineering manager for water and gas.
The surveys found 75 main and 142 service leaks, all of which are already repaired or will be repaired within the timelines required by the federal Department of Transportation. Of the city's 23,502 installed gas meters, fewer than 2.5 percent needed to be leak-tested and repaired.
"The City of Palo Alto is the pre-eminent natural-gas utility in the country in replacing natural gas lines. As a proactive measure to provide safe service to homes and avoid ruptures in the system, CPAU replaces every gas line in the city in 34.5 years (6 miles per year of distribution and 600 service lines), well before the expected lifetime of any pipe," Scoby stated in a press release.
Palo Alto has been actively replacing its aging pipeline infrastructure for earthquake safety and is scheduled to rebuild its gas-transmission points in 2011, according to Clerkson.
To control the corrosion of steel pipelines, the city has cathodic protection, a procedure using electrical current that prevents corrosion on the line.
Corrosion of steel lines could lead to gas leaks. Utilities staff follow routes each month to check the steel system and to ensure that cathodic protection is working, Scoby said.
Currently, 69.2 miles of steel gas mains and 1,152 miles of steel gas services are protected.
The utilities department handled more than 7,000 service requests in 2009.
About 45 percent of these requests were regarding natural-gas issues, most of which concerned pilot light re-lights and new gas-meter installations.
Customer-service representatives, who handle more than 36,380 calls per year, are trained to answer natural-gas safety questions. Dispatchers are available 24 hours a day to respond to customers' safety concerns when they smell gas, the department said.
"If you smell a hint of natural gas, leave the premises and call the city's dispatch center at 650-329-2579, or if there is a significant smell of gas all around the area, leave the area on foot and call 9-1-1.
"Safety is everyone's responsibility. The City of Palo Alto is grateful both to its customers and employees for working together to make sure that we are all safe," Valerie Fong, utilities director, said.
More information on gas safety is available at www.cityofpaloalto.org/civica/filebank/blobdload.asp?BlobID=8059.
The department sends gas-safety information to customers multiple times each year and conducts an annual telephone survey to see whether customers understand what to do to stay safe around natural gas.
The most recent annual telephone survey, completed earlier this month, included a randomly selected statistical sample of about 7,500 customers, plus an equal number of non-customers for a total of about 15,000 calls.
The results from these annual surveys guide the development of natural-gas safety education programs for the upcoming year, according to Scoby.
For more information about safety programs at CPAU, visit the "Utilities Safety Information" link on the Utilities Department home page at www.cityofpaloalto.org/utilities.