A/HRC/27/55 D. Violations of the obligation to refrain from discrimination and to ensure substantive equality 55. The prohibition of discrimination is of immediate effect, while positive measures and programmes to ensure substantive equality may require resource allocation and infrastructure development over time. The prohibition of discrimination allows for, and in many circumstances requires, differential treatment and other measures designed to eliminate systemic or structural discrimination. To identify inequalities, and progress towards eliminating them, States must develop monitoring mechanisms and collect disaggregated data.63 Moreover, States are obligated not only to eliminate discrimination resulting from State action or inaction, but also to “immediately adopt the necessary measures to prevent, diminish and eliminate the conditions and attitudes which cause or perpetuate substantive or de facto discrimination” including discrimination by private actors, 64 which must include measures to combat stigmatization. 65 Moreover, the Convention on the Rights of Persons with Disabilities explicitly stipulates that denial of reasonable accommodation constitutes discrimination (art. 2). 56. Examples of violations of the right to equality and non-discrimination can be grouped in the following categories: (a) Exclusion of groups or individuals from services or facilities, or failure to take measures to achieve substantive equality and address systemic patterns of inequalities; (b) Failure to reasonably accommodate persons with disabilities and take into account particular requirements; (c) Failure to prevent and combat discrimination and stigmatization in the private sphere, or endorsement of stigmatizing practices through State action; (d) Failure to monitor inequalities in access to water and sanitation and to collect disaggregated data for that purpose. 1. Exclusion from facilities or services or failure to address systemic inequalities 57. Inequalities in access to water and sanitation are often due to systemic neglect or exclusion. Courts have successfully adjudicated on discrimination in provision of water, and the requirement to prioritize access by marginalized groups in order to remedy systemic discrimination. In a case in Florida, the court ruled that the municipality could not implement any infrastructure in white majority areas until the African-American majority areas that lacked provision of water were on par with those areas. 66 The European Committee of Social Rights also ordered remedial action including “a positive obligation of authorities to take such [disproportion] into account and respond accordingly” to improve the situation with regard to housing and water for Roma.67 Violations of the rights to water and sanitation of indigenous peoples is evidence of historic patterns of colonialism and 63 64 65 66 67 16 Committee on Economic, Social and Cultural Rights, general comment No. 20 (2009) on nondiscrimination in economic, social and cultural rights, para. 41; E/C.12/2002/11, para. 53. Committee on Economic, Social and Cultural Rights, general comment No. 20, para. 8. A/HRC/21/42, para. 82. United States Court of Appeals, Eleventh Circuit, Dowdell and Others v. City of Apopka, Florida, 698 F. 2d 1181, 28 February 1983. European Committee of Social Rights, European Roma Rights Centre v. Portugal, Complaint No. 61/2010 (30 June 2011).