Environmental evaluation of coal combustion by-product utilizations

Historically, coal combustion by-products such as bottom ash and fly ash have been considered mineral resources suitable for recovery and utilization. With the passage of the Resource Conservation and Recovery Act, interest in developing and commercializing technologies to utilize these by-products has gained considerable momentum. Presently there are numerous utilization options at various stages of technical and commercial development: the use of coal ashes in highway construction, cement mixtures and manufacturing, soil conditioning, land reclamation, mineral recovery and special physical/ chemical reagents. An environmental evaluation of proposed by-product utilizations is essential to ensure that the substitute material will not cause unacceptable environmental or health effects. This paper outlines a step-by-step environmental evaluation approach to be incorporated in the progressive decision-making process of developing candidate technologies toward commercialization. Its application would help ensure, in a timely and cost-effective manner, that no regulatory violations or unreasonable hazards are associated with the proposed utilization. The methodology is divided into two successive stages of increasing precision. In the first stage, the environmental evaluation is completed to the extent of revealing insurmountable regulatory or environmental problems. The second stage addresses those issues remaining irresolute after the first stage is partly or completely performed. Activities appropriate to each stage are detailed showing decision points, appropriate source materials and presently available standards for regulatory and impact interpretations. Finally, the logic of the methodology is discussed in terms of practical application, management considerations, and relationships to EPA procedures. © 1982.