Groundwater control is an important factor on many sites to control erosion, prevent migration of contaminants, or keep groundwater from entering excavations or below grade structures. Jet grouting and soil mixing prevent the migration of contaminants. Compaction grouting fills voids and fissures to reduce seepage. Cement and chemical grouting create grout curtains for seepage control beneath dams. TRD constructs continuous cutoff walls with very low permeability. Polyurethane grouting seals concrete joints. Hayward Baker has experience with the full range of groundwater control techniques to provide effective groundwater control.