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SR-416-004 (2) . . CM:JG January 12, 1988 '116-00L/ Santa Monica, California rNFORMATION ITEM TO: Mayor and City council FROM: City Staff SUBJECT: Automatic Gas Turn-off Valves INTRODUCTION The following outlines the pros and cons of installing automatic gas turn-off valves to insure against gas leaks in the event of an earthquake. DISCUSSION Features of the Automatic Gas Shut-off Valve Product In recent years, several manufacturers have introduced automatic gas turn-off valves which can be installed at the meters of private residences, businesses and institutions. Such valves are designed to turn off gas flow to meters in the event of an earthquake of moderate magnitude, thereby mitigating against the gas leakages which can trigger explosions and fires after an earthquake. Installation of automatic gas shut-off valves has been criticized due to their tendency to be triggered by any sizable vibration, - 1 - . . be that vibration a mild earthquake or the result of movement of nearby heavy equipment. Whenever such a mal function occurs, a Gas Company representative or a licensed plumber must restore gas service to the affected user. When this issue was discussed with a seismic engineer currently being used by the City to design an earthquake bracing program for City structures, he commented that although the product has malfunctioned in the past, many of the shut-off valve products currently on the market have been perfected to insure that the automatic shut-off feature is only triggered by substantial ground shaking resulting from a moderate to severe earthquake. Position of the Southern California Gas Company The Southern California Gas Company has developed a position paper on the installation of automatic gas shut-off valves, a copy of which is attached for Council review. In essence, the Gas Company questions both the reliability of the product and the necessity of installing such devices to mitigate against gas leakages and fires in the event of an earthquake. In particular, the Gas Company argues that, based on the behaviour of the gas line system in past earthquakes of moderate to severe magnitude, very few fires resulted from gas leakages and, as such, automatic shut-Off of gas flow to residences and businesses was not warranted. In addition, considerable delays in the restoration of gas service could result were Gas Company employees forced to perform system tests on hundreds or thousands of residences after an earthquake. As such, individual - 2 - . . residences and businesses could be forced to go for days without the comfort of gas service. Position of City staff It is the opinion of City staff that, although individual homeowners and businesses may elect to install automatic gas shut-off valve devices, it is not advisable for the City to require their installation due to the potential for product malfunction, the past performance of gas systems under moderate to severe earthquakes, and the procedures for central gas shut-off by the Gas Company in the event of a severe magnitude earthquake. It may be advisable, however, to investigate the installation of such devices on all City facilities since the City employs several staffmembers qualified to restore gas service in the event it is shut-off. Such installation would help to insure that City structures were protected in the event a moderate to severe earthquake occurred during evening hours when City structures are sparsely staffed. - 3 - "- :( . . ~ ~ II __ __ .. I 6 I ~~ SOUTHERN CALIFORNIA 19_osl COMPAND - -" 100 EAST NUT'NOOD SfI'IEET . 'NGLEWOOC. CALIFORNIA NORMA L GONZA!..ES Dtstpct Manage" MA'L1f';G ADDRESS 1228 FIFTH SfREET SANT... MONICA CALI~Ol=iNIA 90401 (213) 330 2277 (213) 393 0395 January 7, 1988 Ms. Lynn Barrett, Assistant City Manager Santa Mon1ca 1685 Maln Street Santa Monlca, Ca. 90401 Dear Lynn: Thank you very much for your telephone call advising me of the upcoming study session next Tuesday, January 12, 1988. Enclosed for your 1nformation 1S the Southern California Gas Company's background paper on "Earthquake Shutoff Devices For a Building's Gas Piplng System.ll Will you please feel free to call me 1f I may be of help. Cordially, '4 -L~ d / r;L, . -!-~-.P,-_ NLG: cb Attachment cc: B. R. I>lare .. . . . . BACKGROUND PAPER: Earthquake Shutoff Devices For a Building's Gas Piping System Introduction Commonly~ aftex each major earthquake, numerous proposals are made at the state and local levels of government to mandate natural ga8 automatic shutoff devices. Southern California Gas Co. (SoCalGas) believes there is no compelling evidence to warrant mandating the public to spend millions of dollars installing this equipment. For example, 'preliminary information from tbe recent Whittier earthquake shows that only five minor fires, resulting in an estimated $2,000 in ~otal damage, were caused by broken natural gas. lines. At the same time, as many as 3 million customers would have been without service if shutoff devices had been mandated. This paper explains the gas company's position on proposals ~o mandate the installation of automatic shutoff equipment. It includes a brief explanation of how the devices operate and problema presented by their operation_ Also included is a summary of experience from previous earthquakes, a brief description of the gas company's emergency procedures and steps customers can take to improve the safety of their natural gas appliances in the event of an earthquake. ~ow Dev~ees Operate Only three earthquake shutoff devices have been approved for sale in California by the state architect. Each of them closes off a buildinq's natural gas supply when vibration or ground acceleration reaches a predetermined level. They will do this whether or not damage has occurred to the gas lines they are designed to protect. For example, earthquake shutoff equipment has been known to be triggered by vibrations from an earthquake that is centered miles away. During the recent Whittier earthquake, these devices abut off natural gas to homes as far away as Riverside (45 ailes). None of the gas lines to these homes were damaged during the earthquake. ~e~~oring ,~erv1ce Because theEe is 80 much more involved than merely turning ~he meter back on, only a licensed plumber or trained gas company service Eepreaentative is fully qualified to restore natural gas service after it has been interrupted. -1- . . ~ When ou~ service people resto~e service, they close the pilots on all appliances and check to make sure there a~e no leaks in the system. They also make su~e that ai~, which may have been allowed into the piping by the gas being shut off. 1s purged from the system before ~eli9hting the appliances. Additionally, ou~ se~vice ~epresentatives inspect ell the gas appliances to make certain they a~e operating and venting properly. . Restoring natural gas service properly to one home normally takes from 20 to 30 minutes. More time would be needed if a potential problem is detected. AfteE an earthquake. it likely will take awhile until a service person can get to the home to reset the shutoff device and restore service. For example, during the Whittier earthquake. 21,074 customers turned off their gas needlessly. It took approximately 150 people, workinq lO-hour shifts, one week to resto~e service to everyone. The restoration problem would have been astronomical if shutoff devices had been mandated. SoCalGas estimates 3 million of the company's 4.37 million customers would have been without se%vice. From two to three months and mo~e than $25 million in needless expense would have been ~equl~ed to put all customers back on line. Emergency Procedures In any emergency situation, our primary concern is to protect the public safety. Thus, during an earthquake, we first would check our system and repair any leaks or pipeline breaks that might have occu~red. We also would restore service to facilities needed during the emergency, such as hospitals or evacuation centers. Resetting closed earthquake shutoff devices would be a low priority and would be done only after all emergency conditions are resolved. There are 9as company employees, ranging from executives to service people, on-call 24-hours-a-day. In the event of an earthquake, they.know where to go and what to do. Some employees. for example, will check our major pipelines to dete~1ne if any have been damaged and must be shutdown. At the same time, other employees will report to the company's Emergency Response Center. These employees will monitor activities in the field, make needed policy decisions and coordinate efforts to obtain equipment or people from other parte of the company ox other utilities. The company's emergency p~ocedu~es are tested during extensive, annual training exercises. Company representatives also pa~tlcipate in appropxiate community committees dealing with emergency prepa~edness issues. . -2- . . Experience From Previous Earthquakes Experience from earthquakes since 1933 indicates that natural gas leaks and resulting fires have been minimal. No fires involving natural gas occurred during the earthquake in Palm Springs in July 1986. Also, only three minor leaks were discovered in customers' house piping. All of the leaks were at appliance connections, and two of the three may have existed before the earthquake. Mexico City, which experienced an earthquake measuring 8.1 on the Richter Scale in September 1985, does not have a gas distribution system similar to that of SoCalGas. In Mexico City, residents use a mixture of liquid propane and butane tbat is stored in tanks on the roofs of buildings. However, a town, just 20 miles north of Mexico City, does have a system similar to OurS. In this town, as well as Mexico City, there were no deaths, fires or explosions attributed to natural gas leakage caused by the earthquake. On Oct. 15, 1979, an earthquake measuring 6.5 on the Richter Scale shook Imperial Valley. There were no deaths, but property damage fram the temblor was valued at millions of dolla~s. Still. the earthquake caused no major damage to company gas lines and there were no natu~a1 gas related f1res. About 75 gas leaks in homes may have been caused by the earthquake. About 45 of these apparently occurred when water heaters toppled. Although 98 mobile homes were jolted 1ram their supports, no natural gas fires resulted. On February 9, 1971, an earthquake measuring 6.4 on the Richter Scale shook the San Fernando Valley and surrounding areas. The earthquake resulted in the loss of 64 lives and millions of dollars in property damage. None of these deaths and very little of the property damage can be attributed -to natural gas leaks. A summary of calls to the Los Angeles Fire Department on February 9 and 10 showed the Lollowing: o ~ere we~e no calls due to explosion from natural gas. · o There were 28 reports of natural gas leakage that did not involve fire in the San Fernando Valley area and 13 in other areas served by the department. o 7bere were three calls in the San Fernando Valley and three from other BEea. in the department's jurisdiction involving fires associated with natural gAS. The total estimated loss due to fire damage was about $4,300. -3- . . o There wexe six requests in the San Fernando Valley and 10 from other areas served by the department to respond to fires associated with heating equipment (gas or electric). The cause of one of these fires was determined to be the earthquake. The others did not have a cause noted. The total estimated loss due to these fires was less than $12,000. A report published by the u. S. Department of Commerce after this earthquake states;. "In general, the gas system sustained the stresses of the earthquake remarkably well. This was borne out by the fact that in many areas where appreciable damage occurred to buildings, tbe gas system remained intact." The report further states that although there were isolated instances where water heaters overturned and broke 1008e* .... damage to buildings by fires associated with gas was nil or relatively minor." California's worst experience with earthquakes occurred in San Francisco in 1906. Historical records indicate that the fire that followed the earthquake was not caused by escaping gas, but primarily by wood, coke and coal fires that spilled onto combustible floors. The fires raged out of control because there was a shortage of water, caused by broken water mains, to fight them. Since then, technology and fire departments' capabilities have improved significantly, making a repeat of this experience unlikely. Info~ation on the 1933 Long Beach earthquake also is sketchy. However, our review of accounts and examination of photographs do not indicate that fire was a cause of great damage. It also should be noted that the Long Beach experience resulted in building code changes so all structures built since then are more quake resistant. Implication~ of Automatic Shutoff After the Sylmar quake 1n 1971, gas was the only utility service available in many areaS for comfort heating, cooking and sterilization.of water. The health of infants, the eldeEly. the Inf~r.m and others could be impaired if they have to go a long- while without natural gas for beat, sterilizing water and cooking unrefrigerated food. Because existing earthquake shutoff equipment is triggered by movement, rather than indication of a leak or pipeline break, many people would be without se~vlce needlessly. Still. they would have to wait until a gas company service pe~son or a plumbeE-could get to their homes to check the system and restore service. ~b18 could evolve into a dangezDD& situation if someone were to become impatient and ~ry to restoE. service himself. Furthermore, aftershocks can repeatedly close the reset earthquake valve. -4- II f i j : J ! . . ~ Alternatives to Shutoff Valves If an individual wants the extra feeling of security that migbt come from knowing that his or her natural gas service will be closed automatically during an earthquake, then he or she may want to install a shutoff device. The Gas Company does not object ~o this voluntary action. However, a person who smells gas can easily shut off the service himself or herself with an open-end, adjustable wrencb that Is heavy enough to provide the leverage needed to shut off the service. Instructions on how to shut off a meter with a wrench are ~istributed regularly to our cus~omers. Instruc~ions, with illustrations, also are in the .Survival Guide" of the telephone directory. Customers can also take advance precautionary measures by stabilizing their natural gas appliances to prevent gas lines from twisting and cracking_ Hot water heaters, for example, should be strapped to a nearby wall to help prevent them from moving or falling over. In addition, this would protect what might be the only sanitary water souxce available after an eartbquake_ Conclusion There is no compelling evidence that mandatory installation of earthquake shutoff devices is needed to prevent fires resulting from natural gas leaks during an earthquake. In addition, experience indicates that many homes and businesses would be without a fuel needed for survival for an extended period of time. Therefore, SoCalGas does not believe homeowners should be forced by law to spend millions of dollars to install earthquake shutoff equipment. Southern Californ!a Gas Company OCtober 1987 ~ -5- . J1.JJru 55-/ . /-/c. -?r AGENDA CITY COUNCIL STUDY SESSION ON EARTHQUAKE PREPAREDNESS JANUARY 12, 1988 6:00 PM I) Introductory Comments (5 minutes) II) Location and potential for Seismic Activity Involving the city of Santa Monica (20 minutes) Tom Heaton, Chief Seismologist u.S. Geological Survey, Pasadena III) Earthquake Preparedness Training and Coordinated Earthquake Response Plans (20 minutes) Laura Hernandez Emergency Services Coordinator IV) Pros and Cons of Automatic Gas Shut-off Devices (10 minutes) Julia Griffin V) Seismic Safety Requirements for structures (20 minutes) Bill Rome Building Official Peggy Curran Director, Community and Economic Development Department " - 1 -