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Sustainable reclamation and water management practices 275

14.3 Reclamation practices

At contemporary mines, reclamation strategies are often fully integrated with mining
plans and operations because management of geologic materials is essential to achiev-
ing environmental goals. Overburden, interburden, and/or in-seam partings are all
waste materials that are being handled and managed at every step of the mining pro-
cess. These materials vary widely in their chemical and physical properties and hence,
in their potential to influence postmining revegetation and water management. In this
chapter, the term overburden covers all noncoal waste material that must be dealt with
in the reclamation process.

14.3.1 Overburden analysis
Overburden characterization is essential to mine planning and environmental con-
cerns. Traditionally, overburden characterization has focused on identification of
highly acidic “toxic” materials. For reasons discussed earlier, overburden analysis
also addresses potentials for release of TDS and Se.
Both chemical and physical properties of overburden are important considerations
for material management. Subsurface drainage structures require hard, durable rock.
Topsoil substitutes, if permitted, should have both chemical and physical properties
that are suited to the postmining land use. Any overburden materials intended for
placement in locations exposed to environmental waters should be selected to mini-
mize release of acids, TDS, and Se.
The amount and distribution of acid and alkaline strata (the mineralogy of rock
types) disturbed by the mining operation, along with various interactions, ultimately
controls the acidity or alkalinity of the drainage [10,11]. Therefore, premining ana-
lyses of soils, overburden, and materials immediately underlying the coal are required
by law to ascertain the physical and chemical characteristics of the strata above and
below the coal bed. Overburden characterization provides important information
about rock strata that are acid forming, neutral, or alkaline producing, as well as strata
that may promote drainage waters high in TDS, Se, or other problem elements.
A number of tests are available for overburden characterization and they can be
broadly defined into static (whole rock) or leaching techniques ([12,13]a). Each
has specific uses in premining water-quality prediction. Since SMCRA requires coal
operators and regulators to predict whether water-quality concerns may occur at a
potential mine site, the analysis is critical to provide a quick and accurate prediction
and to limit the long-term liability and expense of treating a polluted water discharge.
The most common static test for overburden analysis is acid-base accounting. It
characterizes physical and chemical properties of rock strata in terms of its acid or
alkaline production potential. In the method, each rock strata is identified by rock
type, color, and thickness. Ground samples of each rock strata are subjected to sulfur
analysis to determine their acid-generating potential, and to carbonate analysis to
determine their alkaline-producing potential. These potentials are then combined to
evaluate the likelihood for acid or alkaline drainage [10,11,14,15]. Acid-base