The south-eastern region of Gunung Kidul, Java, Indonesia, consists predominantly of karstic structure. This region, which is mostly rural, is one of the poorest areas in Indonesia and is periodically suffering from water scarcity due to only seasonal precipitation and due to its karst structure. In the frame of an IWRM project, water which flows through an underground river is pumped and distributed to the people. Increasing amounts of water supply in a domestic or economic environment will lead to rising quantities of sewage in the service area. Moreover, karstic ground water is extremely vulnerable to pollutants. Therefore, the basic challenge is to protect the underground river water, and to improve the economic situation of the people at the same time. This leads to crucial questions concerning managing domestic wastewater in the region.
The aim of the dissertation is to develop a methodology to select the most appropriate and sustainable wastewater treatment technology and management for rural karst areas in developing countries. To support decision making in wastewater technology and management, a comprehensive assessment on current sanitation related conditions (institutions, water and wastewater infrastructures, technologies, current mainstream) and their gaps regarding the intended sustainability goals is firstly required. Therefore, a set of sanitation related indicators (derived from Helmholtz concept of sustainability) is developed. Based on this assessment, appropriate measures can be designed towards a more sustainable sanitation situation. For this purpose, a set of multi-criteria indicators which provides a holistic assessment is developed for the evaluation of the appropriateness and sustainability of the different wastewater treatment technologies. Several wastewater technologies will be evaluated, such as: on site (single and several households level), semi off site (communal level, 50 - 200 households), and off site (communal level, > 200 households). A case study on a rural karst area in Gunung Kidul, where this IWRM project takes place, is used for the application of the indicator sets and assessment methods. The expected result of the dissertation will be a methodology for the selection of the most appropriate and sustainable wastewater technology and management, and recommendations for the case study area based on the developed methodology.