ARIJ Water and Environment Research Department aims to provide the public with data about status of the environment in the OPT, which can be used as the basis for formulating policy papers. Specifically, the water and environment research department seeks to identify existing environmental problems, locating sources of environmental pollutants, and measuring the extent of their impact. Through the use of technology ARIJ also evaluates and tries to solve environmental problems; thus identifying the best scenarios for development trends and their effects on the environment.

The Water & Environment Department maintains a laboratory, hydroponics unit and a weather station. These lab instruments are used to test samples for different research outputs, to forecast impacts of climatic change and to monitor changes in water consumption in the OPT, in addition to conducting different experiments on water variability and utilization. Moreover, the department staff study and analyze existing environmental problems, focusing on environmental monitoring and applying computer-based programs to create environmental information systems. The work of the water & environment department also involves conducting basic researches on urban vegetation, air quality, and water management in the Jordan valley.  In its strategy ARIJ works to build the capacity of both the public and the policy makers, through conducting awareness programs regarding environmental problems and their means of remedy. In this area the institute conducts environmental consulting services and feasibility studies, including site assessment; design construction of landfills, and remediation activities.  .

In addition to assessing the environmental sustainability for a future Palestinian state, ARIJ aims to apply its research to introduce new strategies regarding the management of natural resources. Particularly, the Water and Environment Department aims to adopt feasible approaches in the management of waste, testing and introducing environmental technologies targeted towards reducing the solid-waste hazards and air pollution, and implementing pilot projects in the field of waste water. And since shortage in water supply is one of the main constraints to the Palestinian agriculture ARIJ is involved in installing friendly small and medium scale waste water treatment units in a number of Palestinian villages. As for solid waste, the water and environment department produces composters and distributes composting units to Palestinian farmers working with the Sustainable Agriculture staff who also train the farmers on the use of composters.

In the field of environmental sustainability and as another pilot intervention, ARIJ works with local municipalities for building their capacities in applying agenda 21 which is a Palestinian initiative responding to UN Chapter 28. The purpose of the initiative is to provide local and national authorities with the required support to create more sustainable communities by applying an integrated and participatory approach to local policy making. This approach integrates environmental, social and economic sustainability objectives, and engages all sectors of the community in the decision making process and the democratic discourse.