Use of Leaching Environmental Assessment Framework to Evaluate Beneficial Use of Coal Ash
Citation:
Thorneloe, S. Use of Leaching Environmental Assessment Framework to Evaluate Beneficial Use of Coal Ash. 2nd Virtual Global Ash Seminar, NA, Online, December 14, 2021.
Impact/Purpose:
Invited lecture on the use of EPA's Leaching Environmental Assessment Framework (LEAF) to evaluate the use of coal ash and other materials or industrial by-products to ensure that potential leaching of metals to ground water and surface water bodies does not occur as environmental drivers change. Materials management practices over time is reviewed along with the LEAF methods and its application in evaluating coal ash use.
Description:
Worldwide, ash is used as a substitute for portland cement and other materials where more energy and natural resources are required. Metals such as mercury, arsenic, chromium, boron, and selenium are found in coal ash. Use of the Leaching Environmental Assessment Framework (LEAF) is described in how it was used to evaluate the range of coal fly ashes used in the U.S. in making products. Flue-gas desulfurization gypsum was also evaluated as a replacement for mined gypsum. This presentation provides an overview of materials management and how LEAF is used for evaluating potential leaching in future decades from the use of coal ash and other materials. The presentation also provides a review of LEAF to evaluate potential coal ash uses and to evaluate if future leaching of metals occurs for the environmental drivers that can change over time affecting the mobility of arsenic and other metals. Several reports with findings from evaluation of different coal ash applications are identified along with a report providing 10 case studies of the use of LEAF for making cementitious products including a Roman aquaduct. The range of applications evaluated show that coal fly ash can be safely used for the types of coal ash that are found in the U.S.