A/HRC/15/31 In this regard, their activities are intrinsically linked to the realization of human rights, and therefore they need to observe particular requirements in exercising due diligence. IV. Main challenges from a human rights perspective 29. From a human rights perspective, it is imperative to determine whether service delivery contributes to or undermines the realization of human rights. Therefore, the provision of services must be assessed against the standard of the human rights to sanitation and water. While all aspects of these rights, that is, availability, safety, acceptability, accessibility, affordability, participation, non-discrimination and accountability,28 have to be met, some will become more relevant than others in the following discussion. 30. The challenges in the water and sanitation sector are huge. Many of these challenges are faced by all service providers, State and non-State, and thus this analysis may be relevant in a broader context. However, the present section retains a specific focus on situations where non-State service providers are involved, clarifying the obligations of States and the responsibilities of non-State actors in this context, since the human rights analysis changes when non-State actors become involved. By identifying the challenges in the context of water and sanitation service provision, it is hoped that concrete and practical guidance may be offered to States and service providers alike. Against the standard of the human rights to water and sanitation, a number of such challenges can be identified, including: • Guaranteeing transparent and democratic decision-making • Addressing power asymmetries in the bidding and negotiation process • Reaching the poorest and most marginalized • Ensuring affordable services • Avoiding disconnections in cases of inability to pay • Ensuring the quality of services • Ensuring regulatory capacity and enforcement • Ensuring monitoring and follow-up capacity • Establishing effective complaint mechanisms • Addressing corruption 31. These challenges can be encountered at various stages of engagement with non-State service providers. Human rights have to be protected before and throughout the process, requiring a constant assessment, both by States and service providers, of whether the measures taken contribute to the realization of human rights. In the present section, both State obligations and the responsibilities of non-State actors will be addressed in relation to the challenges encountered. Starting with the decision to delegate service provision, the independent expert highlights questions regarding participatory and transparent processes, instruments for delegation and human rights impact assessments. She specifically addresses provision of services to previously unserved and underserved areas. In the operation of services, it is observed that regulation is essential, but often not sufficient to meet the standards of the human rights to water and sanitation and must be complemented by social 28 Committee on Economic, Social and Cultural Rights, general comment No. 15, para. 12; A/HRC/12/24, paras. 69-80. 11