Tenth International Conference on The Constructed Environment

Abstract

Combustion of coal to generate electrical power has been used for over 100 years and has resulted in billions of tons of waste residuals, mainly fly ash and bottom ash. The coal combustion residuals (CCRs) were frequently transported using water for disposal mainly in on-site basins. Commonly, these basins were unlined and often located adjacent to other surface water bodies such as rivers and lakes. It is not unusual to find ground water contamination beneath and down gradient of these disposal sites. On April 17, 2015 the US Environmental Protection Agency promulgated a comprehensive set of requirements for safe disposal of CCRs. These rules promote recycling and beneficial use over disposal. This paper explores questions of sustainability as they relate to the disposition of CCRs. To some, the only acceptable disposition is for utilities to excavate legacy CCRs, transport and redispose in lined landfills constructed in accordance with the current state of the art. This approach can be compared to other approaches such as beneficiation and cap-in-place by exploring questions of local and global sustainability of each of the approaches.