Groundwater pollution is prevented by the use of geosynthetic clay liners (GCLs) as barriers. Granular bentonite (GB) is placed between woven and non-woven geotextiles in the GCLs. The GB seals and fills the intergranular voids upon hydration. High ionic strength ions in the leachate inhibit granule swelling and have an impact on bentonite's sealing capacity. The GCLs eventually fail as liner systems to arrest the leachates. Non-conventional GCLs are recent entrants that contain polymer-amended GBs as a barrier material. The water-adsorbing polymers absorb a large quantity of water to form the hydrogel. The hydrogel fills the intergranular voids of the bentonite and helps the GCLs to contain salt leachates. The waste load in the landfills often places some overburden stresses on the GCLs. The performance of compacted polymer amended granular bentonite (GBP) under high ionic salt concentrations under mechanical load is needed for long-term applicability in liners. This study assessed the volumetric and hydraulic behaviour of GBP at various concentrations of calcium salt and mechanical load environment. The influence of the concentration of pore-fluid and different overburden stresses was considered in this study. It was determined that a decrease in overburden stresses and an increase in pore-fluid concentration correspond with an increase in hydraulic infiltration rate. The underlying mechanism for hydraulic infiltration behaviour is also presented.