E/C.12/2002/11 Page 8 Refugees and asylum-seekers should be granted the right to water on the same conditions as granted to nationals; (g) Prisoners and detainees are provided with sufficient and safe water for their daily individual requirements, taking note of the requirements of international humanitarian law and the United Nations Standard Minimum Rules for the Treatment of Prisoners;18 (h) Groups facing difficulties with physical access to water, such as older persons, persons with disabilities, victims of natural disasters, persons living in disaster-prone areas, and those living in arid and semi-arid areas, or on small islands are provided with safe and sufficient water. III. STATES PARTIES’ OBLIGATIONS General legal obligations 17. While the Covenant provides for progressive realization and acknowledges the constraints due to the limits of available resources, it also imposes on States parties various obligations which are of immediate effect. States parties have immediate obligations in relation to the right to water, such as the guarantee that the right will be exercised without discrimination of any kind (art. 2, para. 2) and the obligation to take steps (art. 2, para.1) towards the full realization of articles 11, paragraph 1, and 12. Such steps must be deliberate, concrete and targeted towards the full realization of the right to water. 18. States parties have a constant and continuing duty under the Covenant to move as expeditiously and effectively as possible towards the full realization of the right to water. Realization of the right should be feasible and practicable, since all States parties exercise control over a broad range of resources, including water, technology, financial resources and international assistance, as with all other rights in the Covenant. 19. There is a strong presumption that retrogressive measures taken in relation to the right to water are prohibited under the Covenant.19 If any deliberately retrogressive measures are taken, the State party has the burden of proving that they have been introduced after the most careful consideration of all alternatives and that they are duly justified by reference to the totality of the rights provided for in the Covenant in the context of the full use of the State party's maximum available resources. 18 See arts. 20, 26, 29 and 46 of the third Geneva Convention of 12 August 1949; arts. 85, 89 and 127 of the fourth Geneva Convention of 12 August 1949; arts. 15 and 20, para. 2, United Nations Standard Minimum Rules for the Treatment of Prisoners, in Human Rights: A Compilation of International Instruments (United Nations publication, Sales No. E.88.XIV.1). 19 See General Comment No. 3 (1990), para. 9.