Evaluation of Potential Leaching of Mercury and Other Constituents From Coal Combustion Residues

Collaborators

Florence Sanchez, Assistant Professor of Civil and Environmental Engineering
David Kosson, Professor and Chair of Civil and Environmental Engineering
Rossane Delapp, Research Engineer of Civil and Environmental Engineering

Abstract

In December 2000, EPA announced its intent to regulate mercury emissions from coal-fired electric utility stream generating plants. The burning of coal in electric utility boilers generates residual materials including fly ash, bottom ash, boiler slag, and wet flue gas desulfurization (FGD) scrubber solids and sludges. These residual materials are collectively referred to as "coal combustion residues" (CCRs). Currently, ca . 70% of CCRs are land disposed (in a monofill or surface impoundment) and the other 30% are reused or recycled for commercial uses such as production of wallboard, cement, and asphalt. Changes in Hg control technology requirements for coal-fired electric utility power plants will cause changes in the dominant chemistries of fly ash and wet FGD scrubber solids and sludges. Within this framework, EPA/OSW has been asked to provide guidance on appropriate testing for evaluating the CCRs resulting from the new mercury control technologies.


The specific objectives of this project is to provide technical guidance to the USEPA and their contractors on the overall program experimental design, sampling procedures, test methods selection, methods implementation, and data reduction and interpretation to evaluate the impacts of enhanced mercury emissions control technology on the potential for leaching of mercury and other constituents from coal combustion residues.