Solid waste management and landfill leachate has been investigated widely for waste treatment and environmental safety. This study aimed to 1) remove organic contaminants from landfill leachate by sole or combined biological and chemical methods, 2) investigate the solid waste management situations in Canadian First Nations communities, 3) evaluate the feasibility of landfill leachate for plants irrigation, and 4) remove nutrients and salinity from leachate and soil by means of phytoremediation. Aerobic sequencing batch reactor (SBR) with activated sludge was used as the biological treatment to remove ammonium. The chemical treatments included ozone (O3), ozone + hydrogen peroxide (O3 + H2O2), Fenton’s reagents (H2O2 + Fe2+), and ozone + Fenton’s reagents (O3 + H2O2 + Fe2+). Results indicated that ozonation of raw leachate achieved 16% COD removal after 240 min of treatment while O3 + H2O2 achieved 33% COD removal of raw leachate with 900 mg/L H2O2 in 120 min. Moreover, the COD removal from raw leachate was only 33% by using Fenton’s reagents. After biological stabilization, ozonation removed 52% of the COD within 240 min. The Fenton’s reagents achieved 67% COD removal using equal doses of H2O2 and Fe2+. However, Fenton’s reagents in conjunction with O3 removed 69% and 72% COD in 120 min and 240 min, respectively. The dosage test also revealed that the 2:1 ratio of H2O2 and Fe2+ had the best COD removal. Two native halophytes Puccinellia nuttalliana (Alkaligrass) and Typha latifolia (Cattail) were selected in this study to investigate bioaccumulation of Sodium (Na+) and Chloride (Cl-) in greenhouse condition. Different treatments were applied on same soil condition, namely control (C), fertilizer (F) and diluted landfill leachate (LL). The results shown that alkaligrass and cattail accumulated 6.86±0.96 and 7.00±0.20 g Na+/Kg biomass with the irrigation of LL, respectively. Alkaligrass and cattail irrigated with LL accumulated 120.15% and 94.48% more Cl- than control. Another test by using cattail to remediate polluted soil (PS) from waste dumping site shown that electrical conductivity (EC) of PS was decreased from 245.0±1.4 ms/m to 51.9± 9.3 ms/m. Na+ and Cl- content in cattail grown on PS was 10.82±1.85 and 64.69±9.15 g/Kg biomass, respectively. The hydroponic test showed that Na+ and Cl- accumulation was 55.53±4.82 and 78.22±28.28 g/Kg biomass. Overall, these results concluded that the combination of biological and post-chemical treatment methods can effectively remove organic contaminants from mature landfill leachate and the selected plants can significantly accumulate Na+, Cl- and nutrient in their biomass.