Coal Ash Landfill Design, Permitting, and Operational Support, Iowa

SCS Engineers was retained to evaluate options for future management of coal combustion residuals (CCR) from a coal-fired power plant in Iowa, as its ash ponds were reaching capacity.

SCS evaluated CCR management options, including enlargement of the existing ash ponds, construction of a CCR landfill on top of a closed ash pond, and construction of a CCR landfill on a greenfield site. After completion of a geotechnical investigation and analysis, construction of a CCR landfill on top of the closed ash pond was selected as the best alternative.

Since then, SCS has worked on a variety of CCR management projects at the plant. Project benefits have included:

• Design and construction of the new CCR landfill on top of the closed ash pond provided approximately 15 years of additional disposal capacity without expanding the CCR management footprint on the site
• Ongoing engineering and planning support provided by SCS has assisted client staff in managing the CCR proactively and cost-effectively

The services performed here by SCS Engineers included:

• Completed feasibility analysis for CCR disposal options
• Engineering design and permitting assistance for a CCR landfill
• Supported the operation of the CCR landfill and compliance maintenance over many years, providing general operating assistance, financial assurance support, environmental monitoring and surveying assistance
• Site survey, landfill disposal calculations and capacity estimates
• Feasibility study of disposal of the new waste streams resulting from mercury controls and sulfur dioxide scrubbing system
• Final cover phasing details, plans and review of alternative cover design
• Evaluation of the future landfilling options with respect to permitting, constructability concerns and costs