Waste from coal-cleaning is extremely acid. Unlike soil, in which the colloidal complex controls physical and chemical behavior, coal waste chemistry appears to be controlled largely by strong acid. Soil test procedures can be applied to coal waste, but results cannot always be interpreted in the same manner as for soil. The Mitscherlich-Bray concept for phosphorus and potassium availability is invalid in coal waste due to confounding effects of iron and calcium. “Lime requirement” methods are not necessarily invalid, but the quantities of limestone eventually applied to the growth media may become ineffective. Extractants for metals in soils should be applied to coal waste with caution, due to changes in pH during the extraction. Particle size analysis by sedimentation, and single-value moisture constants, are generally invalid for coal wastes, but “available water” concepts have about the same applicability as in soils. Simple convective-dispersive models are applicable to solute transport in coal waste, but the major retardation reaction in the material may not be adsorption, as it is in typical soils.