Non-hazardous solid waste generated during construction of the Project will be disposed of at an approved off-site landfill. This waste will consist primarily of waste wood, paper, scrap metal, and other items. Recycling of construction waste will be carried out to the extent practical.
Solid waste produced during operation of the Project will consist primarily of bottom ash, fly ash, and FGD wastes. These waste products will be collected and disposed of in the existing on-site landfill, which will be expanded as part of the Project.
Expansion of the current 110-acre on-site landfill to 188 acres will provide 15.4 million cubic yards for coal combustion ash and similar wastes. Minimum longevity calculations provide for closure of the landfill as early as 2036; however, the ultimate capacity could be extended to 2066 and beyond, depending on operating conditions and final configuration of individual units.
The design of the landfill has included extensive testing of the in-place ash material, a review of site geology and hydrology, and aquifer modeling. Studies of the existing landfill by the Electric Power Research Institute (EPRI) conclude the in-place waste will be stable and substantially moisture-deficient, which means the landfill will absorb rain and snow for hundreds of years.
The moisture-absorbing characteristics of the waste material combined with the native, evapotranspirative final cover planned for the site have been modeled to determine its effectiveness for protecting the groundwater.
The landfill design provides for sequential construction of 11 cells over time. A system of synthetically lined storm water run-off collection ditches will be constructed concurrent with cell development. The lined collection ditches transmit storm water runoff that may come in contact with the waste to a synthetically lined impoundment for storage until evaporation. The design of the lined collection and basin management system provides a closed loop that ensures runoff does not contact the surrounding environment.
Protection is further verified through a network of early-detection monitoring wells surrounding the landfill cells. The monitoring network is sampled at regular intervals and for up to 30 years following closure of the landfill site.
Sunflower established a trust fund, as required by Kansas law, to provide for third-party closure, maintenance, and long-term care for up to 30 years following closure of the landfill. The trust agreement also provides for long-term monitoring of groundwater resources in the vicinity of the landfill site.
Small amounts of hazardous wastes will be produced during both construction and operation of the Project. These wastes will be collected and temporarily stored on site in a properly designed storage area prior to off-site disposal at a licensed hazardous waste disposal facility.
A modified permit from the Kansas Department of Health and Environment (KDHE) was also required for the expansion of the on-site landfill. The proposed expansion of the landfill follows a successful 27-year operating and environmental history at the site. During this period, no environmental issues or non-compliance situations have been identified by the KDHE.