Design and Construction for Coal Combustion Residuals Landfill Closure

Background

MidAmerican Energy Company (MEC) owns and operates the Louisa Generating Station in Iowa. As part of the implementation of the Coal Combustion Residue (CCR) rules, MEC engaged us for closure of their on-site unlined landfill and build a new lined landfill with zero leachate discharge for future CCR management. We worked with MEC to develop the landfill Master Plan and provided permitting, design, bid support, construction management and quality assurance for MEC to meet the regulatory requirements.

Approach

For closure of the unlined landfill, we performed an air space analysis to support continued disposal during design and construction of the new lined landfill and developed a phased closure approach to facilitate stormwater management and minimize risk.

For the new lined landfill, we led the design efforts and implemented innovative ideas like a gravity leachate collection system and zero discharge leachate management. We installed a groundwater monitoring network to support the new lined landfill which required a hydrologic investigation and report, and the development of a hydrologic monitoring system plan. To facilitate successful permitting of a new lined landfill, we developed an Emergency Response and Remedial Action Plan, Development and Operations Plan, Fugitive Dust Control Plan, Storm Water Run-On Run-Off Plan, Closure Post-Closure Plan, Threatened and Endangered Species Survey Report and a Location Restrictions demonstration.

In addition to design and build out of the first landfill cell, construction of the new lined landfill included a one mile extension of power and communications from the main facility to support landfill operations; non-potable water well; lined leachate management pond; overhead load out rack and associated controls for non-potable water and leachate; stormwater retention pond; and assistance with design and management of institutional controls for threatened and endangered species in the project area.

Results

Working collaboratively with the MEC team, we assisted the client to maintain compliance with the Federal CCR rules and delivered a solution that reduces potential future risk and liability. Our innovative approaches to leachate management and our expertise in design and permitting landfills is providing MEC with a comprehensive solution to dry ash disposal. MEC recognized our expertise and requested that we assist another consultant to employ a similar strategy we had developed at this facility at another one of their facilities to direct closure of CCR landfills.