DO YOU MANAGE A COAL COMBUSTION RESIDUALS IMPOUNDMENT?
The US EPA published new criteria for classification of solid waste disposal facilities and practices on April 17th, 2015. Based on their effective date of October 19th it’s pivotal that you understand your owner operator inspection requirements for Coal Combustion Residuals (CCR) disposal units.
Based on type and designated hazard level you will be required to secure services for:
To complicate matters many CCR impoundments that contain earthen fill embankments are subject to state dam safety regulations based on their hazard level classification.
Due to recent events, the Virginia Department of Environmental Quality (DEQ) is moving towards classifying all ash impoundments as high-hazard dams. In Ohio, most ash impoundments are Class II (medium-hazard) structures by the Department of Natural Resources. In addition to regular inspections, many of these impoundments are required to have Emergency Action Plans (EAP) and Operation, Maintenance & Inspection (OM&I) Manuals in place. If original, engineered construction plans are not available, the dams may be required to be assessed for stability. The assessment would include a geotechnical investigation, slope stability analysis, hydraulic analysis of spillway systems and an as-built survey.
It is important to note that ash impoundments that are no longer in use may be removed from regulatory requirements by a formal closure process. A pond closure may include removal or regrading of the ash, capping of the ash material with clay soil or a liner, breaching of an embankment, or some combination thereof. Design considerations include: stability of remaining embankments, lowering of the water table within the impoundment, capping of remaining ash with an impervious material, monitoring of water levels during and after construction, and revegetation and reclamation of the site.
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