Earthquake: The Hidden Disaster
Out of sight, out of mind. In the lead up to most inclement weather, an onlooker can see the approaching tornado, hurricane or ice storm. An earthquake is a different matter, especially given the rarity of strong earthquakes that feel like anything more than construction in the distance. Lacking visual stimuli to remind them of the natural disaster’s threat, people may take precautions for weather conditions (storm shelters, evacuation routes, and supply stockpiling), but fail to prepare for the possibility of an earthquake. This attitude is unwise for most of the United States, where only North Dakota, Minnesota, Wisconsin and Florida are considered completely seismic-free. Most vulnerable—and most populous—are the Northeast, Southeast, Midwest, and the states west of the Rocky Mountains.
The rarity of strong earthquakes in the Southeast and the Midwest should not obscure the fact that their seismic zones have the capacity for disastrous earthquakes. The East Tennessee Seismic Zone (the Appalachian Seismic Zone) is capable of producing a magnitude 6 earthquake and the New Madrid Seismic Zone, covering parts of Illinois, Indiana, Kentucky, Tennessee, Mississippi, Arkansas, and Missouri, produced three magnitude 8 earthquakes in 1811 and 1812. Seismologists estimate that earthquakes of this magnitude occur on average every 400 to 600 years. However, there is no way of knowing whether the next “big one” will occur tomorrow or hundreds of years from now. One thing that seismologists do agree on is that it is not a question of if, but when.
Experts estimate that every 75 to 100 years the New Madrid Seismic Zone produces an earthquake of about 6.0 magnitude—powerful enough to do significant damage. The last one was 1895. “We’re overdue,” said Jim Wilkinson, executive director of the Central United States Earthquake Consortium in Memphis, Tenn.
The Wabash Valley Seismic Zone, which includes three of the seven states that are also in the New Madrid zone, is capable of producing magnitude 7 earthquakes, which is stronger than was estimated even a few years ago. “The Wabash erupted with a 5.2 in April 2008 that was felt in 12 to 14 states, and caused damage in three,” said Wilkinson. And, of course, there is California, where dozens of earthquakes rock the region on a daily basis. In fact, it may be the only state where people think about earthquakes more often than weather disasters.
Earthquakes in the Midwest are harder to predict than in California because Midwestern quakes occur miles below ground, covered by loose soil. About 200 minor earthquakes occur each year in the New Madrid zone, most of them are too weak to be felt by humans.) In California, the faults are visible on the surface, and motion detectors can be set up to measure fault movement, which can aid in prediction.
The loose soil in the Midwest causes another problem. For example, while a magnitude 5 earthquake in California might cause shaking in one or two counties, an earthquake of similar magnitude in the Midwest can cause shaking across several states because shockwaves travel through the soil from deep under ground. The earthquakes of 1811-1812 that occurred in Missouri were felt on the Eastern Seaboard.
“A powerful earthquake in the New Madrid zone would have a regional impact, not just a community impact, and we see it as a very serious threat,” said Wilkinson. “There would be a direct impact to utility generation, transmission, and distribution.” There would also be an indirect impact, such as curtailed coal supplies as a result of railroad track and bridge damage or destruction. “Barge traffic carrying coal to power plants near the Mississippi River would also probably come to a halt,” he said. The soil near the river is more vulnerable to shaking.
In fact, much of the soil in the New Madrid zone can be subject to liquefaction during earthquakes, which is the inability of the soil to hold whatever is on it—almost a quicksand effect. “This would make generating stations, substations, transmission towers and distribution poles subject to damage or even collapse,” Wilkinson said.
His biggest concern related to utilities is that a powerful earthquake could compromise the national grid, in that it could affect areas far outside of the New Madrid zone, including the East Coast, and even into Canada. Furthermore, many of the major natural gas pipelines running from Texas and the Gulf of Mexico to the Northeast run through the middle of the New Madrid Seismic Zone. A major earthquake could disrupt power to that area in another way. “There are pumping stations every few miles,” he said. “A lot of them are remotely controlled. There are shut-off valves every mile or so. However, how well they would perform in an earthquake is unknown.” If the power system and communication systems are down, it may not be possible to shut them down remotely.
Wilkinson’s group has had some planning initiatives, but it has been difficult to get utilities in the region to participate, he said. “Memphis Light, Gas & Water participated in at least one,” he said. “However, we need more involvement from utilities.” The Central United States Earthquake Consortium needs to know what utilities’ plans are. The consortium is trying to work with Midwest Independent Transmission System Operator and Tennessee Valley Authority. “They have some extensive modeling capabilities, such as what would happen if a certain plant or substation goes down, and how things can be rerouted in the grid.” This kind of information would be immensely valuable to the consortium as it works to develop a regional earthquake response plan.
According to Callen Hays, crisis management coordinator for the Memphis Light, Gas & Water Division, the utility’s Water, Engineering & Operations Department has taken the lead in recognizing the New Madrid Seismic Zone as a real threat to the system.
“You can go awhile without electricity, but you can’t go very long without drinking water,” said Hays. Hence, MLGW’s first focus was on water. In 1989, Memphis began seeking Federal Emergency Management Agency grants for retrofitting its pumping stations for seismic activity. The utility pumps all of its water out of underground aquifers. The utility has been awarded about $4 million in federal money so far to retrofit four of its eight pumping stations, and it has a grant application in the works to try to retrofit another one.
In terms of gas, Memphis started a project to retrofit its cast iron gas system. “This would also help us out if an earthquake occurred,” said Hays. “Since 1991, we have spent about $48 million to replace about 200 miles of cast iron gas pipe.” In the last couple of years, the utility began focusing on the electric system, too. It hopes to get grants to retrofit this.
These initiatives came after the utility examined its success and failings after a series of windstorms in 2003, which resulted in power outages for more than 300,000 customers. Central to these reforms have been the creation of Hays’ position, ensuring that someone is dedicated to thinking about crisis situations, and building of an emergency operations center, where personnel involved can gather during a disaster and have the resources they need. The same building that houses the emergency operations center holds all of the utility’s call centers, IT, emergency operations, hookups for laptops, five large-screen TVs, customer outage data, and 36 dedicated phone lines. The building is resistant to seismic activity and designed to withstand a 7.0 earthquake. There are six tables for crisis team members: electricity, water, gas, logistics, support, and finance.
The utility also has tried to strengthen its mutual-aid agreements. “At the time of [the 2003 windstorms] we had a lot of east-west mutual-aid agreements, rather than north-south,” said Hays. “Since weather tends to travel west to east, we realized we needed some north-south agreements.” In addition, the utility is working on seeking agreements with utilities that would be outside of the impact zone of an earthquake.
Memphis tries to remind customers constantly about things they can do to prepare for and deal with earthquakes. In the communications area, for example, the utility occasionally has mailers on earthquake preparedness included with bills and produces a local television show.
Kennett, Mo., is another public power community in the New Madrid Seismic Zone. Kennett’s preparations began in 1989 after a climatologist and business consultant warned of the potential for a powerful earthquake in the Midwest. While the earthquake never occurred, the false alarm pushed Kennett and other communities into preparation mode. “We went through a lot of effort then to get prepared, such as putting anchors on our substation transformers so they wouldn’t ‘walk’ off the foundations,” said Larry Jones, superintendent of utilities.
“Clean water is an absolute essential,” he said. “We have a written plan to try to conserve water.” The city has one 1.5 million gallon ground water tank. An elevated tank may not topple during a powerful earthquake, but it probably would be drained immediately because of ruptures in underground water lines. “As a result, we have a plan to shut off all the pumps on the groundwater tank in the event of an earthquake so we can save that water,” said Jones.
Mayor Roger Wheeler Sr is a strong proponent of preparation and continues to spearhead a community-wide emergency planning effort. Because the city owns its electric generators, it would be able to restore power more quickly than communities who purchase power from other parts of the country, Wheeler said.
Recently, the city received a rapid response vehicle, which is loaded with satellite communications devices. “If we have a really strong earthquake, we may be landlocked between the St. Francis River and the Mississippi River,” said Wheeler.
The city completed a comprehensive inventory of all equipment that could be used in an emergency situation, such as trucks, tractors and generators. The city also has commitments from several area farmers who own large farm equipment with blades and front-loaders. They are included on the city’s first-response call list.
In the meantime, the city’s emergency preparedness group has executed training drills with their equipment. “We have also done some cross-training, so anyone in any department can take on whatever task might be necessary,” said Wheeler. For example, firefighters are learning to operate bulldozers, excavators, and road graders belonging to the street department. The reason, according to Wheeler, is that there is a high probability the city would have as much as a 50 percent loss of personnel as a result of a major earthquake.
“We’re not completely ready, but we are certainly promoting the idea that we need to be,” said Wheeler.
The Sikeston Board of Municipal Utilities in Missouri also has comprehensive earthquake preparedness plans. “Our first priority would be to try to restore power to the hospital, the health clinics, and then to the office for emergency operations,” said Edward Throop, general manager. “We would also man the water plants and wastewater plants, as well as the substations and transmission facilities.”
Since the plan was developed, the utility has implemented construction practices designed to protect local infrastructure from earthquake damage. Substation structures and equipment, water towers, and ground storage tanks are designed and built to meet seismic zone standards.
Sikestonhas three portable gas-powered generators that can be used in the office, warehouse and water plant facilities.
“We also have two electrical feeds into the city, one from the south and one from the west, in case our plant would go down,” Throop said. The utility has mutual-aid agreements with other utilities through the Missouri Joint Municipal Electric Utility Commission.
Poplar Bluff Municipal Utilities & City Cable in Missouri has built its new water towers to seismic standards.
“In 1991, we updated our emergency plan for earthquake preparedness. Through this plan we have constructed our main primary lines above ground with subdivisions and single-phase taps being placed underground,” said William Bach, PBMUCC general manager.
If a large earthquake occurred, Bach believes it would be relatively easy to restore power. The utility has responded quickly when ice storms and other disasters have caused outages, he said.
The water and sewer services would pose the biggest problem because the underground pipes would rupture. “We have helped so many other utilities during ice storms and hurricanes with electric service restoration,” he said. “If we have an earthquake, we may have to ask other utilities to send water and sewer crews”
The utility has a peaking plant with about 400,000 gallons of diesel on site. If natural gas were no longer available, the plant could run on diesel. If the line between the tank and the facility ruptured, the utility has a means of isolating it and pumping oil through a transfer hose. “We wouldn’t be able to keep the whole town running, but we could cover emergency services, such as hospitals, Bach said.“
The West—While earthquake planning and preparedness is somewhat new to utilities in the Midwest, it is a way of life for utilities in the West. California utilities plan for and respond to earthquake damage more than any other type of disaster.
According to Bill Carnahan, executive director of the Southern California Public Power Authority in Pasadena, communities with public power utilities actually have an advantage over communities served by investor-owned and cooperative utilities when it comes to natural disasters. Prior to accepting his current position, Carnahan was the utilities director at Riverside, Calif. “Most utilities tend to make plans based on protecting and then ultimately restoring their system after a disaster,” he said. For a public power utility, though, the first priority would be dealing with other more serious emergencies in the community. “In Riverside, we always figured it would be a fair amount of time before our crews were out putting power lines back up,” he said. “Most of our crews and heavy equipment would probably be involved in rescue operations under the guidance of the fire department and/or police department.” In Riverside, procedures called for the utility to report to whoever was in charge of the emergency operations center.
While restoring power to the general public may be a secondary priority, it is still a priority. “The city gets to decide how, when and where to send crews and equipment,” he said. “If you’re served by a non-public power utility, which serves a number of cities and a wider area, they decide when and where they will start restoring power.”
Southern CaliforniaPublic Power Authority has a transmission and distribution emergency operations committee that makes sure it has mutual-aid agreements in place. “After Hurricane Katrina hit the Gulf, we went through an exercise here on disaster,” said Carnahan. “We also do benchmarking studies and best practices in terms of maintenance, construction, reliability, etc.” All of the joint action agency’s member utilities are named in the studies, so anyone reading them knows which members have best practices. “This allows these utilities to contact other utilities with best practices and get information on what they are doing in specific,” he said.
The Northern California Power Agency in Roseville has generation resources but no transmission or distribution. “Most of our facilities have seismic capabilities designed into them,” said Ken Speer, assistant general manager of generation services. However, the agency’s dispatch center has an emergency backup dispatch center in the event of a loss of power or loss of the facility. At the agency’s hydro facilities, there are procedures in place that require inspections after earthquakes of a certain magnitude. “We also spec dams and other critical facilities,” said Speer. “We have similar requirements for our combustion turbine facilities, where we have anhydrous ammonia. We want to make sure that doesn’t leak after an earthquake.” The agency inspects its natural gas pipelines after earthquakes of a certain magnitude.
Anaheim Public Utilities has plans in place on the electric and water sides. The city has an emergency operations center that is managed by the fire department in collaboration with the utility. The emergency response team meets every month with two water representatives and two electric representatives from the utility to discuss earthquake preparedness.
“We also have our own disaster response plans for electric, which are updated every year,” said Manny Robledo, electric operations manager. “We have our main control center here, but we have a back-up control center across town, which is fully functional with SCADA, satellite phones, system maps, etc.”
All of the utility’s substations are battery-operated, so they don’t need power to energize or de-energize the stations. The utility has emergency generators for city facilities. Warehouses are stocked with essential repair materials and fuel.
“We also have an aggressive tree-trimming program, which would reduce outages caused by fallen trees during an earthquake,” said Robledo.
The utility coordinates disaster response with the city’s emergency operations center, public safety, and community services departments. “We try to restore critical load first, such as if the city sets up a community building for citizens to congregate,” he said. “We also have a contract work force available in case we need to supplement our city crews.” In addition, the utility has contract generators on call for areas that it cannot re-energize right away.
“We also have a very robust system, a 69-kV to 12-kV loop system, so if there is a break in any of the 69-kV lines, power can be fed around through the loop,” said Robledo. “We get most of our power off the grid, with external transmission controlled by the California ISO.” Restoration would be coordinated with the Western Electricity Coordinating Council regional security coordinator, in compliance with North American Electric Reliability Corp. standards. “However, if we were separated, we have an internal generator that could pick up some circuits independently,” he said. “We have about 10 percent of our load covered. We are planning to add about 200 megawatts, which would take it up to about 40 percent.“
Plans are equally active and robust for the water services emergency response. “A few years ago, we made an assessment of our water facilities, specifically for seismic retrofit,” said Mike Jouhari, water operations manager. Anaheim made several improvements to its facilities. For example, during a seismic event, failure usually tends to occur where the water pipe connects to the reservoir. To address this, the utility inserted flexible couplings to help absorb any seismic induced movement that might occur. “We also have a couple of portable generators to utilize at our water facilities if there is a power outage,” said Jouhari.
The utility updates its disaster response plans and conducts relevant exercises for water every year. In 2007, it was involved in the state’s Golden Guardian exercise, which is a statewide disaster preparedness exercise. “We activated our [emergency operations center] to level 3, which is the highest level,” said Jouhari. “We will participate in the Golden Gaurdian exercise again this year. We also do our own exercises within the city.”
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