AN ASSESSMENT OF COAL RESOURCES AVAILABLE FOR DEVELOPMENT

CENTRAL APPALACHIAN REGION
by
M. Devereux Carter and Nancy K. Gardner

U.S. Geological Survey Open-File Report 89-362

Chapter 4 - RESTRICTIONS USED

For this summary report, the restrictions to mining were subdivided into two major categories - land-use and technologic.

Land-use restrictions are placed upon mining by societal policies to preserve those surface features or entities that could be adversely affected by mining. Land-use restrictions, therefore, may change if societal interests change. Land-use restrictions largely apply to surface mining, but may also affect underground mining. Technologic restrictions affect the economics or safety of mining and are determined by current levels of technology; these can only change with advances in science and engineering or changes in economic conditions. Technologic restrictions affect both surface and underground mining, but are generally more prohibitive to underground mining.

The restrictions to coal mining and the criteria applied in each of the four study areas are summarized in Table 1 and described briefly below. Detailed discussion of the restrictions and criteria are included in the study area reports cited in the Study Areas and References Cited sections. The major land-use restrictions to mining are delineated in the Surface Mining Control and Reclamation Act of 1977 (Office of Surface Mining Reclamation and Enforcement, 1988). These restrictions, or more stringent ones, must be applied within each State - unless waivers can be obtained. The individual study area reports present the authority for the specific restrictions and criteria applied within each quadrangle in terms of citable laws, regulations, or local practices.

4.1 Land-use Restrictions

4.1.1 Land-use Restrictions to Surface Mining Power lines and pipelines.

Power lines and pipelines are present in all four study areas, but were not considered to be restrictive to surface mining in the Vansant quadrangle. In the other three study areas, a 100-ft buffer zone is commonly left on each side of the power line or pipeline. Therefore, a 100-ft buffer line was digitized around each power line and pipeline in these three quadrangles and entered into NCRDS as the areas restricted from surface mining by power lines and pipelines.

Cemeteries.
Surface mining is not permitted in, or near, cemeteries in most areas. In the Sylvester quadrangle, the actual area of each cemetery plus a surrounding 100-ft buffer zone was digitized. In the Matewan and Vansant quadrangles, where 100-ft buffer zones are also required, the cemeteries were too small to digitize from the 1:24,000-scale maps. Therefore, 300-ft and 100-ft squares, respectively, were drawn around the central point of each cemetery to represent the area of unminable coal

Oil and gas wells.
Buffer zones are required and were created around the location point of each oil and gas well in all of the study areas: in Kentucky, 200-ft squares; in the Sylvester quadrangle, circles with 100-ft radii; and in the Vansant quadrangle, circles with 200-ft radii.

Major streams.
In Kentucky and Virginia, a 100-ft buffer zone is required, and was digitized, around streams and rivers with mean annual flow greater than 5 cubic feet per second. In West Virginia, the valley floors of the Coal River and its major tributaries constitute a restriction to both surface and shallow underground mining and were so digitized.

Towns.
In Kentucky, a 300-ft buffer is required and was digitized around residential and public buildings. In Virginia and West Virginia, where areas of population concentration are restricted from mining, the actual population concentration areas were digitized.

Forest preserve.
In the early 1900's, a 15,000-acre tract was deeded to the University of Kentucky with the provision that it never be mined. The portion of the forest preserve that lies within the Noble quadrangle was therefore considered as a restriction to mining and As boundaries mere digitized.

Major roads and railroads.
These were determined to be restrictions to mining only in the Sylvester quadrangle, but, because they were all within the valley floor boundaries, they did not present an additional impact on available resources and consequently were not assessed.

4.1.2 Land-use Restrictions to Underground Mining

Major streams.
In the Sylvester quadrangle, the valley floors of the Coal River and its major tributaries were considered to be restrictive to underground mining of potentially minable cod beds at relatively shallow depths below. Major streams were not considered a restriction to underground mining in the two Kentucky study areas because there were no known minable coal beds below major-stream drainage, and deep coal mining was not restricted below major streams in the Vansant quadrangle.

Towns.
In the Sylvester quadrangle, actual population concentrations were included as restrictions and were digitized. Towns were not considered restrictions to underground mining in the Kentucky and Virginia study areas.

Forest preserve.
That portion of the forest preserve in the Noble quadrangle described above as restricted for surface mining is also considered a restriction for underground mining and the same digitized boundaries were applied.

4.2 Technologic Restrictions

4.2.1 Technologic Restrictions to Surface Mining

Too thin.
According to the USGS classification system, beds with coal thickness less than 14 inches are not considered to be a resource (unless local practice is to mine the thinner coal beds) and, therefore, were not considered in these studies. In the Sylvester quadrangle, local surface mining practices preclude mining of beds with less than 28 inches of coal; thus, any beds with less than 28 inches of coal were considered as restrictive to surface mining throughout the entire quadrangle This factor was not considered a constraint to surface mining in the other three study areas.

Deep-mine barrier pillars.
In be Matewan and Vansant quadrangles, underground mines in shallow coal beds were not considered restrictive to surface mining. However, in the Noble quadrangle, 50-ft buffer zones are customary left around underground mines during surface mining operations, and, therefore, were digitized as restrictions to surface mining. In the Sylvester quadrangle, where a considerable amount of underground mining occurs within 200 feet of the surface, 100-ft buffer zones were digitized around the near-surface active and abandoned underground mines; these buffer zones were considered to be restrictive to underground mining but not to surface mining.

Thicker beds too close above or below a potentially minable coal bed.
This was only considered a restriction to underground mining in the shallow coal beds that were potentially surface minable in West Virginia where the beds were within 25 feet of one another.

Geologic factors.
In the Sylvester quadrangle, areas where coal beds had been eroded away before, or soon after, burial (washouts) were mapped and excluded from resource calculations. Also, inertinite (organic components) in coal that would prevent complete and rapid burning of coal in power-generation boilers designed to burn pulverized coal were detected in two coal beds and included as restrictions to mining. There were insufficient data to include these or other geologic factors as restrictions in the other three quadrangle areas studied.

Too deep.
Although surface-mining depths vary with changes in thickness and character of coal beds and with changes in the lithology of the overburden, 200 feet was assumed to be the maximum possible depth for surface mining in each of the four study areas. A 200-ft overburden thickness line was derived by subtracting the elevations at the tops of the coal beds from the elevations at the ground surface that are stored in the USGS digital elevation models (DEM's) for each study area.

Technologic Restrictions to Underground Mining

Too thin.
In the Kentucky and West Virginia quadrangles, beds with less than 28 inches of coal were considered too thin for underground raining. In the Vansant quadrangle, only those coal beds that were both totally subsurface (requiring access by shaft) and less than 40 inches thick would not be expected to be mined and, therefore, were considered as restricted.

Too deep.
In eastern Kentucky, 1,000 feet 2 generally considered the maximum depth for underground mining. This was applied as a restriction to mining in the Matewan quadrangle. In the Noble quadrangle, none of the coal beds lie below 1,000 feet. In the Vansant and Sylvester quadrangles, depth has not been prohibitive to mining. In fact, nearly all of the extensively mined Pocahontas No. 3 coal bed is beneath more than 1,000 feet of overburden.

Deep-mine barrier pillars.
Barrier pillars around underground mines are required for mine safety in all four study areas. In Kentucky, 50 feet is required; in West Virginia, 100 feet; and Virginia, 200 feet. Therefore, buffer zones of the appropriate width were generated around each active and abandoned underground mine.

Deep mining too close above or below a potentially minable coal bed.
Where deep mining has occurred either above or below another potentially minable bed, the other bed will not be mined if the beds are within a minimum distance above or below one another This distance is generally 40 feet in the Kentucky and Virginia study areas. In West Virginia, local practice sets minimum acceptably safe interburden thickness at 25 feet, but there were no occurrences of underground mining either 25 feet above or below a potentially minable coal bed within the Sylvester quadrangle.

Thicker beds too close above or below a potentially minable coal bed.
When two potentially minable coal beds occur within a minimum distance from one another, one or the other will not be mined. According to local practice, this minimum vertical distance is 40 feet in the Kentucky and Virginia quadrangles, and 25 feet in the Sylvester quadrangle. For these four study areas, where there are not sufficient quality data to indicate otherwise, the assumption was made that the thicker of the two coal beds would be selected for mining.

Oil and gas wells.
For safety, coal must remain unmined near oil and gas wells in underground mines. The same criteria are applied as for land-use restrictions to surface mining described above.

Geologic Factors.
The same geologic factors described above for surface mining apply also to deep mining.

Chapter 3

Chapter 5

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