KANSAS CITY, Mo.— Helicopter flights near Ashland, Neb., and Mead, Neb., will be part of a new study aimed at a better understanding of the subsurface properties at the former Nebraska Ordnance Plant located south and east of Mead, Neb., beginning Oct. 1.
The upcoming study will use an aerial geophysical method known as a helicopter electromagnetic and magnetic geophysical survey, capable of quickly mapping subsurface geology over a large area.
A helicopter will be outfitted with an electromagnetic system supplemented by a magnetometer. The helicopter will fly at an altitude of 200 feet and will follow a preplanned route using a global positioning system to provide optimal coverage of the area. Flight lines will be flown in an east-west direction at approximately 500 feet intervals.
The purpose of the survey is to map the subsurface properties in an area that covers the existing groundwater plumes. The survey data will provide a three-dimensional picture of subsurface resistivity variations which can be related to geology. The data gathered during the survey will be interpreted, and results will be used to further define existing geologic conditions of the plume areas. The survey will be used to provide more details on the bedrock geology, determine the presence and thickness of clay layers, and develop three dimensional pictures of the resistivity of the subsurface. The three dimensional pictures may provide information about subsurface geologic features which influence surface and groundwater interactions.
During the helicopter electromagnetic and magnetic geophysical survey, instruments which transmit electromagnetic signals are suspended beneath a helicopter in a horizontal tube. These flights will pose no threat to people, facilities, homes or livestock. The presence of a helicopter, however, can be startling to people and animals, especially confined animals such as corralled horses and poultry.
The helicopter will not fly directly over cities or towns. We will also try to identify and avoid flying directly over corralled livestock. However, if you have livestock that would be startled by helicopter noise, or if you have any questions about the pending study, please contact the U.S. Army Corps of Engineers project manager at (816) 389-3172.
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Release no. PA-2012-55