Louisville, MS: Deep Soil Mixing (DSM) Containment Wall Remediation, American Creosote Works

Louisville, MS: Deep Soil Mixing (DSM) Containment Wall Remediation, American Creosote Works

Project Description

services-soil-mixing-barrier-walls-louisville1-msSignificant Project Features:

  • Soil mixing to establish a containment wall through lignite seams carrying creosote and creosote impacted groundwater offsite
  • Previous work completed at this Superfund site by Geo-Solutions included installation of a soil-bentonite cutoff wall and shallow soil mixing for creosote impacted soil stabilization.

Project Background:

Geo-Solutions was subcontracted to complete an additional component of the specialty geotechnical construction portion of the American Creosote Works (ACW) Superfund site remediation. Geo-Solutions’ involvement in the work at this site started back in 2012 and 2013 when it was subcontracted to install a soil-bentonite cutoff wall and to stabilize creosote impacted soils using shallow soil mixing with Portland cement.  The containment wall work scope included the installation of a 40 feet deep, 1,350 foot long barrier wall with a minimum width of feet.  The containment wall was designed to have a maximum permeability of 1×10-6 cm/s to prevent the migration of creosote and creosote impacted groundwater offsite through lignite seams. Geo-Solutions installed the containment wall with its Delmag RH-18 drill rig fitted with a 7 foot diameter auger.  Geo-Solutions’ column to column spacing was selected to ensure the minimum wall width was achieved even when the auger deviated in opposite direction in adjacent columns.
Description of Work:

  • Installation and excavation of three test columns.
  • Sonic coring of the test columns
  • Installation of 347 seven (7) foot diameter soil mixed columns.
  • Maximum depth of 43 feet.
  • Soil mix zone ranged in length from 20 feet to 23 feet.
  • Bentonite added to reduce permeability
  • Achieved permeability values in the low 10-7 / high 10-8 cm/s range which was well below specified maximum.
  • Work completed over 12 weeks, including 2 weeks of setup / tear down and a holiday shutdown period of 2 weeks.

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Key Project Objectives:

  • Ensure that the permeability of the target treatment zone, from 20 feet to 40 feet below ground surface, was below 1×10-6 cm/s.

Project Challenges:

  • Drilling adjacent to soft columns. Geo-Solutions is used to drilling adjacent to cured columns (w/ cement).  Drilling at this site required adjustments to normal procedures
  • Drilling through hard lignite seams
  • Winter weather

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