Revision of the Mandatory Standard SI 1505 part 1, dealing with drinking water treatment systems. This proposed standard adopts the requirements of the following four American Standards: NSF/ANSI 42 – 2020 regarding aesthetic effects; NSF/ANSI 53 – 2020 regarding health effects; NSF/ANSI 55 – 2019 regarding ultraviolet microbiological water treatment systems; NSF/ANSI 244 – 2020 regarding supplemental microbiological water treatment systems - filtration. This standard includes national deviations appearing in the standard's Hebrew section, and differs significantly from the previous edition. Both the old and this new revised standard will apply from entry into force of this revision for a year and a half. During this time, products may be tested according to the old or the new revised standard.