Lansing, Iowa
The Lansing Generating Station – Ash Pond Closure is located 3 miles southeast of Lansing, Iowa. Interstate Power and Light Company, a wholly owned subsidiary of Alliant Energy, owns the property. Lansing Generating Station (LAN) currently operates three surface impoundments at the site, of which the Upper Ash Pond is managed as an existing coal combustion residual (CCR) impoundment under the provisions of the CCR Rule. Contaminants of concern at this site include CCR.
SOW included the installation of an ISS berm between two sedimentation ponds at the Lansing Alliant Power Plant. Sevenson utilized a Bauer CMS45 batch plant to mix and pump a slurry consisting of 10% Portland cement to our Bauer RG27 drill rig equipped with an 8-ft. dual rotary drill bit. The RG27 mixed up to 45-ft. BGS to meet the specifications of 10-ft. into the hard native soils. Production ran 24 hours a day, six days a week to shorten the project schedule by 20 working days. In total, Sevenson performed the ISS of 37,381 CY of soil contaminated with CCR. A small boulder field made drilling ISS columns nearly impossible, so the area around the boulders was pre-excavated to avoid schedule delays. Swell was placed in the area around the boulders and was successfully treated to the designated volume of material.