Mining Engineer Terry Ackman
job to a plumber's -- it's his
says, to develop technology that will allow state reclamation agencies to find and plug cracks in the "piping" network beneath Pennsylvania's rivers and streams.Over the past century, those fractured streambeds have allowed water to fill abandoned mining cavities and contaminate surrounding watersheds. Ackman
, a clean water team leader for the U.S. Department of Energy's
(DOE) Federal Energy Technology Center
(FETC) in Pittsburgh, uses more than the naked eye to pinpoint the cracks, however.His
team relies on fresh data collected by a remote sensing system to identify the effects of past coal-mining activities.
"West Virginia, Pennsylvania and Ohio have been extensively undermined," Ackman
says."When you are mining underneath a stream or river, the rock can fracture and intercept the stream channel.That's how water gets into the mine."As the voids fill with water, the pressure creates an artesian flow that returns to the surface and contaminates watersheds with iron, aluminum and manganese.
"Mine drainage is the worst water pollution problem in this region," he
says."The mining industry has helped clean up the region's rivers considerably, but there are thousands of old abandoned mines that still need to be addressed."
That's where remote sensing becomes most useful," Ackman
During the past decade, Ackman
team have used various ground-based geophysical techniques to successfully identify fracture zones, and then have used a polyurethane grout to prevent stream water from draining into the mines.Now they hope to apply the same approach to riverbeds, using airborne reconnaissance technology.
Last February, a helicopter housing a multispectral imaging system (MSS) was brought from its base at the DOE's Remote Sensing Laboratory in Las Vegas, Nev., to fly over Pennsylvania's Youghiogheny River and the 167-square-mile Sewickley Creek Watershed (SCW).The helicopter, operated by Bechtel Nevada Corp. personnel, conducted a thermal survey of the region.
The MSS detects and records electromagnetic energy, including infrared, that comes from or bounces off certain environment features.
Principle objectives of the characterization, says Ackman
, are locating and mapping mining-related fracture zones and features -- including old wells and mine shafts -- in the river, streams and adjacent lands.Significant flows of polluted mine drainage pass through these fracture zones and features to reach waterways from underground mine pools.The temperatures of these flows contrast with those of surface waters.The temperature differences can be displayed in the MSS either as black-and-white contrast sketches or as computer-enhanced color images.
During the helicopter flights, radiosonde balloons were launched, and thermal measurements were taken with hand-held devices to determine true ground thermal measurements.A global positioning system employed satellites to determine the exact location of the helicopter.
The helicopter-based surveys were conducted at night to reduce impacts of solar radiation on the infrared data, Ackman
The data are being analyzed to determine those irregular features associated with past mining activities.The information then will be used, along with other data, to recommend remediation strategies for the affected areas.
The MSS has been used since 1985 to detect disturbed earth and buried caches of chemicals, to assess forest health and to map Texas coastal lagoons.However, this was the first time the technology was used to map discharges from abandoned mines.
"This work is very exciting," Ackman
says."With this map of the area we can make better decisions and develop best management technologies for the 'average problem.' It gives us a holistic view of the whole watershed." FETC
paid $140,000 to bring the helicopter from Las Vegas to do the initial work in the SCW and on the Youghiogheny River.
"We believe it can be affordable," Ackman
says."Like drilling, a large bulk of the cost is mobilization."By sharing the cost, the funding requirements for the individual watersheds are feasible. FETC
, one of DOE's major field organizations, manages and implements a broad spectrum of energy and environmental programs.It employs approximately 1100 federal and support-service contractor employees at its two sites located in Pittsburgh and Morgantown, W.V., and is the largest fossil energy research organization in the United States.
For more information, contact Ackman
at 412-892-6566; e-mail, email@example.com.