High Quality Content by WIKIPEDIA articles! The Department of the Environment is a devolved Northern Ireland government department in the Northern Ireland Executive. The minister with overall responsibility for the department is the Minister for the Environment. The Department's aim is to improve the quality of life for everyone in Northern Ireland through: the promotion of sustainable development principles in all the activities of government and wider society in particular, their application in DOE's responsibilities for land use, air and water quality, waste management and the natural and built environments