International Journal of Water Resources and Environmental Engineering Vol. 3(12), pp. 288-297, 21 November, 2011 Available online at http://www.academicjournals.org/ijwree DOI: 10.5897/IJWREE11.067 ISSN 1991-637X ©2011 Academic Journals Full Length Research Paper Selection of optimum option for sludge disposal in the Guilan province of Iran using rapid impact assessment matrix (RIAM) Aghil Golipour Shoili 1 , Mehrdad Farrokhi 1 *, Hadi Neizehbaz 2 and Hoseyn Alizadeh 2 1 Guilan University of Medical Sciences, School of Health, Rasht, Guilan Iran. 2 Guilan Water and Wastewater Company, TSU, Rasht, Guilan, Iran. Accepted 21 October, 2011 All wastewater treatment processes produce a large amount of semisolid pollutants, especially wastewater sludge. Discharge of sludge without environmental considerations will have many serious effects on public health and environment. The main objective of this study is the selection of optimum option for sludge disposal in the Guilan province of Iran using rapid impact assessment matrix (RIAM) which is a tool to organise, analyse and present the results of a holistic environmental impact analysis (EIA). The effects of five options of sludge disposal (sludge composting, co-composting, grass land application, sanitary landfill and incineration) on four environmental components (physical-chemical, biological-ecological, social and economical) are evaluated via questionnaires which were was addressed to all environmental experts in water and wastewater companies in Guilan province. It was found that there are different optimum options for each environmental component. Based on overall comparison of the options' effects on all the components, the analysis of matrices has shown that co- composting is the best recommended option for sludge disposal in the existing conditions. Key words: Sludge disposal, environmental impact assessment (EIA), rapid impact assessment matrix (RAIM), Guilan province, environmental components. INTRODUCTION All wastewater treatment processes produce a large amount of semisolid pollutants, especially wastewater sludge. Sludge from wastewater treatment is a concentrated liquid, with characteristics that vary according to the type of plant and method of operation. The solid concentration in sludge varies between 1 to 6% by weight (Turovskiy and Mathai, 2006). The treatment and disposal of sludge are two of the most important and complex subjects in wastewater engineering. Discharge of sludge without proper treatment will have many serious effects on public health and environment. Therefore, sludge should be treated before being discharged into the environment. In selecting the appropriate methods for sludge processing, disposal and reuse, considerations must be given to the relevant standards and regulation (Iran EPA, 2005). *Corresponding author. mfarokhikhb@yahoo.com. The Guilan province is located in southern side of the Caspian Sea. In this province, there are various internationally registered natural resources such as wetlands, lakes, rivers, forests, etc. Improper sludge discharge can have adverse effects on these natural resources and public health (Farrokhi et al., 2008). There are three sludge treatment plants in the cities of Rasht and Anzali that at the present produce 40 m3/day of dewatered sludge (GWWC, 2010). Non proper sludge disposal can have adversely affects on these natural resources and public health (Farrokhi et al., 2008). The choice of a sludge disposal system should be based on their environmental effects (Poulsen and Hansen 2003). Different environmental impact assessment (EIA) methods are used for sludge management technologies for example Life Cycle Assessment method used to compare different options for sludge treatment and so as to determine which option is the most environmentally sound (Ngelah and Per, 2008). The main objective of this study is to conduct the selection of optimum option