WASHINGTON (AP) -- Putting a dozen or so chemical plants in Calvert City, Ky., seemed like a good idea 50 years ago. The western Kentucky town is on the Tennessee River. A nearby dam controlling the flood waters of Kentucky Lake generates tons of electricity.
But there is a problem. The town, with its tens of millions of pounds of deadly chemicals, sits in an earthquake zone. Calvert City was built near the New Madrid Fault.
And while its plants are protected against moderate quakes, they are not required to gird themselves against the worst-case disaster: a series of massive earthquakes geologists say could erupt at any time.
As Americans search their backyards for the next Hurricane Katrina, the New Madrid is getting notice. Much of that concern focuses on cities like Memphis and St. Louis. President Bush on Thursday called for a review ''emergency plans in every major city in America.''
But in small towns like Calvert City, there are other threats. Fertilizer factories line the Mississippi River, storing and processing anhydrous ammonia for transport on trucks and barges. Chemical and uranium enrichment plants dot the landscape.
Chemical units built since the introduction of new standards in the late 1980s are required to protect against moderate earthquakes, said Jim Wilkinson, executive director of the Central United States Earthquake Consortium, which coordinates federal and state agencies in the eight-state fault zone.
Yet they are not required to protect against a worst-case scenario, said Victor Weeks, risk management program coordinator for the Environmental Protection Agency's Region 4, ''because in most cases they're not very likely events,'' Weeks said. The EPA, which coordinates with federal, state and local agencies in places like Calvert City, focuses on preventing human error and other accidents, he said.
Geologists have two fears. One is a massive series of earthquakes on the scale of the 1811 and 1812 New Madrid upheavals. Those quakes were so huge _ estimated between 7.3 and 8.2 on the Richter scale _ they temporarily reversed the flow of the Mississippi River and were felt in Canada, said Gary Patterson, spokesman for the University of Memphis' Center for Earthquake Research and Information. The Memphis center estimates a 7 to 10 percent chance of massive quakes on the New Madrid within the next 50 years, Patterson said.
More likely would be a series of moderate quakes rating 6.0, powerful enough to threaten the chemical infrastructure while damaging evacuation routes and leveling parts of cities, Patterson said.
The nightmare for Calvert City would be a resulting cloud of toxic gas like chlorine, said Duane Hawes, Marshall County's director of emergency management. Officials would have minutes to warn the public to stay in their homes and seal their doors and windows. The ability to communicate in the chaos of a major earthquake could mean thousands of lives.
''We've got a lot of nasty things out there that hold a lot of potential for causing harm,'' Wilkinson said. The CUSEC plans exercises in 2007 to prepare for a chemical disaster. But the early stages are temporarily delayed: Talks between the group and the Federal Emergency Management Agency this month were interrupted by Katrina, he said.
The Arkema Inc. plant in Calvert City, which produces resin, refrigerants and hydrochloric acid, follows the guidelines, said spokesman Walter Kramer. New and updated units at the 57-year-old plant, which stores tens of millions of pounds of chlorine, hydrochloric acid, vinylidene fluoride and hydrofluoric acid, are protected against moderate earthquakes. But none are guarded against the most serious categories. Kramer did not know how many units had not been retrofitted.
It is not known how the plants would fare in an earthquake. ''It's going to depend on the severity,'' Hawes said. ''If we get an 8.6, you can't expect really anything to survive that.''
Calvert City's plants are ready for a 4.0 or 5.0 earthquake on the Richter scale, he said. But Hawes worries even a moderate quake could rupture the earth around the Kentucky Dam, flooding Calvert City and its plants, stranding chemical shipments on broken roads and railroad tracks.
Some 100 small tremors strike New Madrid each year, along with a handful of quakes rating 3.0 or above. A smaller fault in nearby Indiana, the Wabash Valley Seismic Zone, produced a small earthquake this month.
Because of soil types and its location in the center of a tectonic plate, geologists say New Madrid quakes spread farther than their California equivalents. And based on the fault's history, the most likely worst-case scenario would be a series of major quakes that could last several months. The ground along rivers could liquify, tumbling chemical stores and pipelines into the water supply.
''Unfortunately, you have to go plant by plant,'' when looking at regional safety, Wilkinson said.
USEC Inc.'s Paducah, Ky., Gaseous Diffusion Plant, which enriches uranium, is protected against major earthquakes and would not pose a radiological hazard, said David McIntyre, spokesman for the Nuclear Regulatory Commission. But a quake could release a plume of hydrofluoric acid affecting areas two miles away, said USEC spokeswoman Elizabeth Stuckle. The plant maintains a fire department for such a possibility, she said.
