With a nuclear power generation facility and several chemical plants in its jurisdiction, Linn County, Iowa, is a likely location for a hazardous materials incident. Although a major disaster has never occurred in the county, local officials have developed an evacuation plan just in case.

The Duane Arnold Energy Center nuclear facility has its own evacuation plan that spans two counties, and Linn County officials modeled their Metropolitan Evacuation Plan after the Arnold Center plan, tailoring it to smaller chemical spills or incidents. The plan safeguards the county's 160,000 residents across five jurisdictions through quick public notification, incident command and mutual aid response.

"The risk is here, but the safety level is very high," says Walter Wright, director of emergency management for Linn County. "We still have the potential to have to evacuate thousands of people." Officials started by dividing the metropolitan area into small sections along major identifiable objects and major streets throughout the county. Three types of maps were developed: a large map outlining the subareas for emergency dispatch centers; sector and subarea maps for response department commanders; and a small sector map for response vehicles.

When a hazardous incident occurs, an on-site incident commander refers to the proper map to determine the area to be evacuated and the cardinal direction in which the evacuation needs to occur. The commander notifies the main dispatch center to communicate the orders to other responding agencies to coordinate the evacuation. The agencies then set off the countywide siren system and communicate the information to the public through the media.

To further aid the public in the evacuation, the county arranged for evacuation maps to be printed in local phone books, which are distributed to all homes, businesses and motels. When an evacuation announcement is made, residents can refer to their phone books for the area being evacuated (e.g., subarea 15c) and the proper escape route.

Incident commanders, such as police and fire chiefs, attend training several times each year to ensure that they are familiar with the evacuation plan, maps and possible scenarios. Incident responders, such as police officers, are trained annually.

The project cost $7,000 for development, printing and distribution of the maps, which was completed in November 1998. The second phase -- phone book printing -- will be completed early this year.