Dense Slurry Ash Management in the Context of EPA Proposed Regulations for Coal Ash and Power Generation Wastewater

摘要

The proposed Effluent Limitations Guidelines (ELG) and Coal Combustion Residuals (CCR)rules promulgated by the U.S. EPA impact the coal-fired power industry significantly. The ruleswill 1) regulate fly ash settling ponds out of existence, 2) regulate the location, design, operationand closure requirements for impoundments, and 3) impose strict new requirements forwastewater management.Traditional “dry ash” management satisfies the requirements of the new rules but suffers frominherent technical deficiencies that are costly and that exhibit inherent safety risks.Dense Slurry System (DSS) technology mixes an optimum quantity of plant wastewater withCCR’s to produce an environmentally stable end product. Once cured, the product exhibits lowhydraulic conductivity, high compressional strength, no transport water discharge, little or nofugitive emissions, reduced leachate volume and enhanced metals sequestration. DSS achievesthe goals of the ELG rules and CCR rules more safely and at a lower cost than that of traditional“dry” ash management.DSS has been used extensively in Europe but is only being used at one plant in the United States.This paper presents some information regarding global DSS operations including a discussion ofhow DSS achieves the goals and objectives of the CCR and ELG proposed rules.