Sometimes the best way to solve a problem is to refer to old solutions; at other times, as every futurist knows, progress is only possible by looking beyond present technologies. Denver Harper, a research scientist at the Indiana Geological Survey, operates in both those worlds.
"There was a medieval iron mining site in Europe," Harper reports, "where the mine was leaching contaminated water into a natural wetland. This system was hundreds of years old, yet it turned out that the wetland was still performing a cleaning action on the water." That research helps confirm that "low technology" methods of mine reclamation may sometimes work better over the long term, and be much less costly, than more standard methods currently dominant. It also illustrates the necessity of gathering all available "old" information, standardizing it, and making it available for unexpected users and uses.
Harper has combined his backgrounds in mining engineering, coal geology, and computing to create new uses for software that generates visualizations of data. Called Geographic Information Systems (GIS), these techniques enable users to look at a site's geological, hydrological, subterranean, aerial, land use, topographical, and other characteristics.
"More than 80 percent of all information has a spatial component, which makes a visual representation a powerful tool," Harper explains. He has devised techniques that import large amounts of data from existing, character-based databases, as well as from old geologic maps, into Geographic Information Systems.
"People want and need all sorts of information," Harper says. "They want it instantly, and they want it on the Internet." For example, a person or institution considering building a landfill might need information about roads, the neighborhood, regulatory requirements, and hydrological and geological conditions of a particular site. Until now that would have required a massive search through a mountain of different types of information; with the application of GIS systems, it will become possible to analyze a site in minutes. "They might find that the third best site geologically is the best for other reasons, so the Geological Survey might be called in to do field testing to refine the assessment," Harper says. "We'll still be needed in the field, but our work will be more precisely targeted than it was before."
The Geological Survey's GIS begins with an overall look at the Illinois Basin--large portions of Indiana, Illinois and Kentucky--where coal deposits are significant. The GIS can reveal different views, including contours, locations and thicknesses of coal deposits, color-coded dots to indicate test sites where drilling has shown problems with trace metals or unstable structures, aerial photographs, development patterns, major highways, existing mines, and other features.
"I'm working right now on a 'flyby' where you can zoom across the buried coalbed, as if it were exposed to the surface," Harper says. "That could give you the pattern of the coal deposits in a given area as well as the rock layers between which they're sandwiched." Alternatively, a user can approach the GIS with a specific question: a utility company might want to locate coal with less than 2 percent sulfur, more than 12,500 Btu, and less than 2 parts per million selenium (a harmful trace metal). Harper inputs that request, and the computer transforms a map of the three-state area into a series of highlighted areas indicating where such coal may be available. "Now the utility buyer doesn't have to rely on someone's word or pay for as much expensive additional testing."
The result looks and seems effortless; yet Harper and his colleague, Karen Like, a database coordinator, along with several others at the Indiana Geological Survey, spent years to make it simple. "We had literally thousands and thousands of reports, core samples, and other information to put into the system," Harper says. All of it had to be standardized. For example, in one state geologists might have considered a "thick" coal seam as greater than 5.5 feet, while an adjacent state would have called the same seam "thick" only if it exceeded six feet. Names of coal seams change as state lines are crossed. Different institutions have used different map projections. Databases utilizing incompatible programs and computer operating systems had to be reconciled.
Currently, those most involved in the development and use of GIS are institutions such as oil, gas, and coal companies, utilities, and governments. "It was a tremendous effort to put the data together," Harper says. "And we're nowhere near done. Literally, the sky is the limit with this software." Harper paraphrases the president of ESRI, a leading GIS software company: "Everything that lives and everything that moves will be measured, if there's a way to measure it." Harper points out that this is an old desire: the desire for omniscience.
Already one database contains all the known petroleum deposits in the world. As people input more data, that database and others like it become more "omniscient." Yet much information remains proprietary and, thus, inaccessible, and that sometimes frustrates the Geological Survey personnel, whose information is generally open to the public. "People come in and say a coal company wants to buy their coal rights, and they want to know whether they should do it; we can give them the information we have, but we may not know enough. But the company knows," Harper says.
People in mined areas also contact the Survey, asking if they should buy insurance against their home or business collapsing (mine subsidence insurance). With the GIS, Harper can provide a printout of a color map of nearby underground mines, which can indicate to the potential buyer whether to proceed. "There's a lot more information we have to get that's already been collected but not computerized, and that needs to be done in the field," Harper says. "There's really no limit to what we can do with this tool."
The GIS system also contains information on reclamation, the most important element of Harper's old-fashioned work as a field geologist. Although many years and much money have been spent on elaborate ways to reclaim old coal mine sites for other uses, Harper admits he has never been comfortable with those technologies. "One concern I've had is that if there's an economic depression, for example, and you just walk away from these sites and don't maintain them, what's going to happen?" With conventional reclamation, abandoned mine sites--usually a series of deep pits with piles of disturbed, dumped, or crushed rock heaped around them--are smoothed out by expensive grading machines. Elaborate man-made drainage systems are installed, and a cap of soil seals in the mined material. "But if somebody goes out there with a dirt bike or something, which happens all the time, and they are able to breach the soil cap or break a drain, the whole system can fall apart," Harper says. Gullies form, and the soil cap washes away. The expenditures are wasted, and the site has to be re-reclaimed.
The western portion of southern Indiana is replete with such sites from years of surface (strip) mining. That's because massive seams of coal several feet thick, which are buried hundreds of feet deep under much of southern Illinois and Kentucky, meet the surface in southwestern Indiana. The point of convergence between surface and seam is called the "crop line," and it's much easier to mine coal there than to dig underground pits and raise the coal to the surface elsewhere. The drawback is that old-style surface mining sometimes left an ugly and toxic landscape behind.
Federal law now requires mining companies to reclaim their active sites; but hundreds of mines in Indiana alone are abandoned--often by companies that no longer exist. Fortunately for the environment, federal laws mandate cleanup of such sites, using funds derived from a fee charged in mining new coal. Geological Survey scientists work with the Indiana Division of Reclamation to improve reclamation techniques.
Far more troublesome than the look of an abandoned mine is the acidic content of the "gob pile," material left behind from the mining and coal purification process. "Indiana coal contains a lot of pyrite, which is very high in sulfur," Harper explains. Once the companies took the coal out of the ground, it went through one or more of several processes called "washing" to lower its sulfur content to a level acceptable for burning. The "gob pile" left behind is sometimes so acidic that nothing will grow in soil contaminated by it or by water that has run through it. Geologists routinely find samples of water near gob piles with a pH of one or two, on a scale where seven is neutral and four or five means something can grow.
One method of battling that acidity is to infuse the gob pile with crushed agricultural limestone. Reclamation teams must use as much as 100 times the amount of limestone typically needed to balance the soil in a regular farm field to detoxify a gob pile. After that process, instead of massive regrading, drainage design, and application of a cap of soil, reclamation concludes with simple straw mulching and planting of vegetation. If the site has wet areas, the marshy conditions will cause the toxins and trace metals to precipitate out of the water. Reclamations try to stimulate the growth of cattails, which will then remove the contaminants. In 1993, Harper received the annual "Innovation Award" of the Indiana Society of Mining and Reclamation for the work that he and his colleagues did in helping to introduce this technique to Indiana.
|Perspective views of three-dimensional surfaces that have been created from engineering drawings can help citizens visualize the effects of construction activities associated with reclamation projects. This computer-generated image shows topography of a reclamation site in Pike County, Indiana, where flyash from the power plant at Petersburg was used in reclamation.|
Support for the GIS project has come from a variety of sources, including coal and utility companies, as well as the U.S. Geological Survey and sister organizations from nearby states. As one system with many sponsors, points of contention exist about how much public can see, a situation which is still to be fully worked out, Harper says.
The GIS system has many applications already, even within IU. The School of Public and Environmental Affairs is building a parallel GIS database on plant and animal species in Indiana and is teaching courses on how to use GIS. Geology colleagues on several IU campuses are also engaging in GIS-based projects, including reclamation of the Great Marsh at the Indiana Dunes National Seashore.
The future, for Denver Harper and others, is clearly in the expanding GIS and in a growing number of collaborations with other computer experts. It can seem at times a long way back to southern Illinois, where Harper's father and two grandfathers were coal miners. "There was never any question that the coal industry was dying and that I would therefore have to do something else with my life," he says. "So I went to school in geology and even, for a time, ended up working for a coal company in an underground mine in West Virginia, where there were a lot of rock falls and gas explosions. It was that experience that really focused my interest on coal geology."
Harper's family history in the coal industry led him into this field. But he and his colleagues at the Indiana Geological Survey are using innovative techniques that are changing the field. The combination of the history and innovations enable him to work at the forefront of new initiatives in both current and futuristic technologies.
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