Abstract: A method of using waste materials produced by coal combustion to produce useful products. In one embodiment the invention provides solid bricks produced by compressing together fly ash, bottom ash, gypsum, calcium carbonate, and lime. These bricks have sufficient structural strength for use in building and construction. In another embodiment, waste materials are encapsulated in a mixture of fly ash, bottom ash, gypsum, lime, and calcium carbonate and compressed into bricks that may be disposed of in an environmentally acceptable manner. Further, the compressed bricks containing waste material may be coated with an impermeable membrane of a synthetic polymeric material. Further, the invention provides a mobile, trailer-mounted apparatus for compressing the mixtures into bricks.