<p>Biochar, a carbon-rich by-product of biomass pyrolysis, is recognized for its long-term advantages in lowering carbon footprint and promoting carbon sequestration. While most research focuses on its agricultural use with fine sand, this study explores an alternative, large-scale carbon sequestration by injecting biochar into coarse-grained soil using permeation grouting. This would significantly reduce atmospheric carbon levels, offsetting current global emissions. Hence, this research investigates the impact of palm biochar on the fundamental properties, compaction, hydraulic conductivity, and compressibility of coarse-grained soil. Sand samples were mixed with biochar contents of 2.5%, 5%, 10%, and 15% by weight, using two biochar gradations. While sieve analysis identified the sand gradation, the laser diffraction methods analyzed the gradation of biochar and biochar-amended sand. Geotechnical properties were determined, including the specific gravity (<i>G</i>_<i>s</i>), using the density bottle method and liquid limit (<i>w</i>_<i>L</i>) using the cone penetrometer method. Compaction tests were carried out using standard effort, and the saturated hydraulic conductivity (<i>k</i>_<i>sat</i>) values were determined using the falling head permeability test. One-dimension consolidation tests were conducted to determine the soil’s void ratio under increasing vertical pressure, and <i>k</i>_<i>sat</i> values were measured with each load increment. Results indicate that the <i>G</i>_<i>s</i>, compression index, and <i>k</i>_<i>sat</i> decrease with increasing biochar content. Finer biochar particles significantly reduce the <i>k</i>_<i>sat</i> compared to coarse biochar particles. Increasing biochar content increases the <i>w</i>_<i>L</i> and the optimum water content and decreases the maximum dry unit weights of the amended sand. However, further research is required to validate the applicability at the field scale.</p>