Groundwater Containment Systems

GAIA has extensive experience in the development and implementation of a variety of groundwater containment systems. Past remediation projects completed by GAIA have included the following:

• Slurry walls – These non-structural underground barriers impede groundwater flow. Typically, this involves excavating a vertically sided trench kept open by filling the trench with a bentonite slurry. The slurry is then displaced with the final slurry wall mixture of either bentonite and soil or bentonite and cement.
• Sheet pile walls – Interlocking sheets of steel or high grade plastic creates a physical barrier to reduce the flow of groundwater, sometimes backed by extraction wells placed up-gradient.
• Waterloo barrier system – A patented system from the University of Waterloo Centre for Groundwater Research which incorporates a sealable cavity within the joints of interlocking steel sheet piles. The joint cavity is flushed, cleaned, inspected and injected with a sealant grout. The result is a barrier approximately as impermeable as a slurry wall, and as strong as a sheet pile wall.
• Hydraulic containment (wells and trenches) – Pumping groundwater from correctly-spaced wells or trenches can effectively cut off groundwater flow and help prevent the spread of contamination. The extracted water can then be treated on-site.
• Concrete caisson walls – To provide a barrier for groundwater, a series of intersecting large diameter holes are drilled to the required depth and backfilled with a cement-grout mixture. When the work is completed, the row of backfilled holes forms a continuous barrier.
• Deep Soil Mixing – Cement and/or bentonite are mixed into the soil in situ to form a soil cement or soil bentonite curtain wall which limits the migration of groundwater. By utilizing the in situ soils to form the wall, the method obviates the need to dispose of soils to form the wall, and the need to dispose of excavated soils which may be contaminated.