NetL

TECHNICAL SUPPORT DIVISION
Ecological Services and Technology Transfer Branch (ESTTB)

NETL Project
Demonstration of Airborne Technologies for the Delineation of Abandoned
Underground Mines in Wise County, Virginia

Photo of Net L electro magnetic conductivity technology in use.
Electromagnetic sensing instrument in flight.

The National Energy Technology Laboratory (NETL), the State of Virginia, and the Office of Surface Mining Reclamation and Enforcement (OSM) have partnered in evaluating the combined application of airborne and ground-based geophysical technologies and geographical information system (GIS) technology as tools for delineating underground mine workings, mapping groundwater flow paths, and targeting potential impoundment failures. In collaboration with the State of Virginia, 3 small demonstration sites (approximately 10 square miles) have been selected in Wise County, VA. Selected mine sites are ones that have been previously characterized and has an adequate amount of hydrologic, geologic, and engineering data that can be used to verify the remote sensing data. The airborne survey of the selected sites has been conducted using a helicopter. (See photo on this page.) NETL has constructed a GIS database of the site, including the airborne data and other available and pertinent data (e.g., mine maps, geology), necessary for interpretations. The GIS database will be used to target field activities for the verification of the airborne data.

Both frequency-domain and time-domain Electro Magnetic (EM) conductivity technologies were employed. The airborne frequency-domain and time-domains EM technologies have a maximum effective depth of penetration (skin depth) of about 300- and 600-feet, respectively. The data-gathering activities of these technologies require that the instruments be flown over the terrain at a constant elevation of about 100 feet. These low altitude surveys require aircraft to fly back and forth over an established area and are very visible to the public. Consequently, NETL worked with Virginia to provide appropriate public notice to State and local law enforcement agencies, media, and other organizations just prior to the implementation of the mission.

The site-specific conditions (primarily depth to underground workings) dictates the selection of the airborne technology that was applied. NETL is uniquely experienced in the environmental application of frequency-domain EM on a large-scale, watershed-basis. However, NETL is also interested and capable of expanding its evaluation of airborne technologies to include time-domain EM. NETL selected the appropriate technology for application based on site-specific conditions and they were responsible for the implementation of the airborne mission and the subsequent data management, processing, interpretation, and verification.

Current Status: Virginia has provided GIS and water quality data from sites to be flown to the principle investigator. This data has been compiled and analyzed by the principle investigator and the Virginia/OSM Steering Team. Three sites were selected to reflect three real world scenarios: 1) a flooded abandoned mine near an active underground operation (Que Creek Scenario), underground works beneath a coal slurry impoundment (Martin County Scenario), and interconnected mine works with AMD (Monongahela River Mine Pool Scenario). The sites were flown on May 22nd and 23rd. NETL scientists are in the process of analyzing the data.

Contact Information:
Office of Surface Mining Reclamation and Enforcement
U.S. Department of the Interior
Appalachian Regional Office
3 Parkway Center
Pittsburgh, PA 15220
Phone: (412) 937-2804

Site Map
getinfo@osmre.gov
03/06/2007

Webmasters message
Please send website comments and suggestions
to Audrey Parker at aparker@osmre.gov

Accessibility Contact
OSM Privacy Policy
Freedom of Information Act (FOIA)
Disclaimer
No Fear Act Information

OSM Home Page
DOI Privacy Notice