This paper shows potentials of developed H-jointed SPSP and proposed H-H joint for application as a vertical hydraulic cutoff wall in coastal landfills. Their construction accuracy, resistance characteristic under lateral load, joint performance, and hydraulic conductivity are assessed through experiments. H-jointed SPSP can control the accuracy of construction and exhibits higher lateral bearing capacity than SPSP with traditional joint connections. H-H joint demonstrates larger tension resistance than traditional joint. Hydraulic conductivity of 10⁻⁸ cmls is proposed for use in design of H-H joint. The H-jointed SPSP with H-H joint is recommended as a hydraulic cutoff wall in coastal landfills.