Labadie, MO: Labadie Slurry Cutoff Wall

Labadie, MO: Labadie Slurry Cutoff Wall

Project Description

Significant Project Features:

  • Soil Bentonite Slurry Wall installed and backfilled using excavators
  • 635 Linear Feet and a Total 18,595 Square Feet Excavated up to 30-feet deep
  • Target Permeability of 1 x 10-6 cm/sec

Background:

The Ameren Missouri power plant is a coal burning complex just north of the town of Labadie, Missouri. The power plant has multiple bottom-ash ponds where groundwater flow needs to be controlled.

Project Objectives:

Geo-Solutions was contracted by Ameren Missouri to install a cutoff wall through one of the levees surrounding their main bottom-ash pond.  This included the installation of approximately 18,000 vertical square feet of cutoff wall installed via the soil bentonite trenching method.

Description of Work:

The cutoff wall was installed from the surface of an existing access road and extended through the main pond emergency spillway.

Geo-Solutions selected a Komatus PC 400 and its own custom stick to excavate to the required depth.

The trench was excavated under bentonite slurry manufactured in Geo-Solutions’ on-site batch plant. Due to space constraints, backfill had to be mixed remotely.  Trench spoils were trucked from the trench to a mixing area where they were blended with bentonite slurry to create a homogenous backfill mix. The backfill was then trucked back to the trench locations and placed in the trench to create a barrier wall which met the requirements set forth by the specifications.

Geo-Solutions served as the prime contractor for the project.  The scope of work for the project also included:

  • Quality control and documentation of excavation, backfill, and slurry properties
  • Spillway stockpiling and reinstallation
  • Installation of an impermeable clay cap.
  • Restoration of roadway and spillway