Based on experiences about the planning of decentralized wastewater treatment systems for slums of two rural towns in India, the paper asks to what extent affordability for the future users may impede the realization of other sustainability goals. The planning aimed at ensuring economic, social, and environmental sustainability. To this end the planning process promoted the participation of stakeholders and it was supplemented by an in-depth analysis (using novel methods) of the socio-economic situation of the future users. In particular, an approach towards estimating willingness to pay from small samples was developed. Taking all this information into account, planning identified a well-established technology that it is inexpensive, robust, and easy to maintain. The experiences of this planning process may generalize to other developing countries seeking socially acceptable low cost solutions with reasonable pollution reduction for resolving the sanitation crisis.

Recent concerns about alleged insufficient water provision to the poor in Detroit, USA, has put the Human Right to Water (HRW) into the international discussion. The paper asks: "To what extent did international human rights treaties make HRW judiciable?" and "How did government policies implement it?" In a crosscountry comparison of performance indicators, merely accepting HRW has not been helpful in promoting affordable access to potable water or sanitation facilities close to the home, amongst the reasons being deficiencies in water-governance. Case-law confirmed that with respect to affordable access HRW obliges governments to a "progressive realization" only, also in countries accepting HRW (India, South Africa). The paper focuses on the resulting positive state obligation to establish funding programs for better water and sanitation services and analyzes funding policies by a mathematical model of policy goals. It identifies two viable goals namely the successful support for the poor, as in developing countries, and the most economic use of public funds, as in industrialized countries. Other goals conceivable for the model have been tried in the past and failed.