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Hydraulic Properties of Coal and Related Materials, Northern Great Plains
Author(s) -
Rehm Bernd W.,
Groenewold Gerald H.,
Morin Kevin A.
Publication year - 1980
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1980.tb03649.x
Subject(s) - hydraulic conductivity , aquifer , geology , lithology , overburden , coal , coal mining , permeameter , bedrock , mining engineering , geotechnical engineering , soil science , hydrology (agriculture) , groundwater , geomorphology , geochemistry , soil water , engineering , waste management
The hydraulic properties (hydraulic conductivity, specific storage and porosity) of coal and the sediments that surround the coal must be known or estimated to properly evaluate the environmental impact of coal strip mining on ground‐water flow systems. Published and unpublished data have been summarized from five study areas in North Dakota, three areas in Wyoming, two areas in Montana and two study sites in Alberta. Coal and sand beds form important aquifers in the region. Both materials have hydraulic conductivities of about 2 × 10 −6 m.s −1 and specific storage values on the order of 5 × 10 −6 m −1 . Aquitards in the region consist of clayey silt to clay bedrock and pebble−loam (in parts of the region). The aquitards are fractured to varying degrees resulting in a wide range of measured hydraulic conductivity values. The aquitards are, in general, 100 to 1,000 times less permeable than the aquifers. Specific storage values of the aquitard material is on the order of 3 × 10 −4 m −1 . The hydraulic conductivity of strip mine spoils has a six order of magnitude range with a mean of 8 × 10 −7 m.s −1 . Variability is due to a number of factors including spatial variation of overburden lithology, method of spoil handling and contouring and time of year during which the spoil is handled. The hydraulic conductivity of the coal shows wide spatial variability within a given mine site. Variability of coal hydraulic conductivity between mines within North Dakota is less than within a given mine. Within the Northern Great Plains the permeability of coal may increase slightly from east to west.