Environmental Modelling & Software 24 (2009) 8–25 1 Fault tree analysis and fuzzy expert systems: Early warning and emergency response of landfill operations I. M. Dokas 1,1 , D. A. Karras 2 , D. C. Panagiotakopoulos 3 1 Dr., Cork Constraint Computational Centre, University College Cork, Cork, Ireland 2 Prof., Chalkis Institute of Technology, Automation Dept. and Hellenic Open University, Rodu 2, Ano Iliupolis, Athens, 16342, Greece 3 Prof., Laboratory of Project Management, Civil Engineering Department, Democritus University of Thrace, Xanthi, 67100, Greece. Abstract In this paper we argue that early warning systems for engineering facilities can be developed by combining and integrating existing technologies and theories. As example, we present an efficient integration of fuzzy expert systems, fault tree analysis and World Wide Web technologies to their application in the development of the Landfill Operation Management Advisor (LOMA), a novel early warning and emergency response system for solid waste landfill operations. The aim of LOMA is to provide assistance to landfill managers on their efforts in preventing accidents and operational problems and to help them to develop emergency response plans if these operational problems shall occur. Additional aim is to disseminate information and knowledge to the public on landfill 1 Corresponding author. E-mail address: i.dokas@4c.ucc.ie, jdokas@yahoo.gr