Membrane filtration is one of the main methods for individual and local water supply systems. Track-etched membranes are among the types of membranes that allow to obtain high quality purified water due to their high selectivity. Ensuring the durability of track-etched membranes is one of the topical issues on their use. Comparative research of the natural water filtration process using standard 12-μm track-etched membrane and new, more durable 20-μm irradiated on both sides was performed. Both membranes were manufactured by NPF TreM, St. Petersburg. The pore diameter of membranes was 0.20–0.205 μm, the pore density was 2.3 × 108 cm–2 and 1.5 × 108 cm–2 , respectively. The research was conducted with natural water from the pond in the park, "Malinovka" (St. Petersburg, Kosygin pr.). The filtration was run in the dead-end model. Raw water and filtrate samples were analyzed by spectrophotometry and spectroturbidimetry using KFK-3.01 photoelectrocolorimeter and SF-56 spectrophotometer. The dispersion analysis of nature water was performed by dynamic light scattering on Zetatrac laser analyze. The experimental data showed the same dependences of the productivity of dead-end filtration of pond water samples upon the volume of passed water and close values of turbidity and color in filtrate samples for both membranes. The results allowed us to recommend the 20-μm-thick membrane irradiated on both sides with a beam of argon ions having a range shorter than the film thickness for natural water purification for local water supply of individual buildings.