Municipal Solid Waste (MSW) disposal is currently one of the major environmental issues in big cities. Several tools and techniques
have been developed for Environmental Impact Assessment (EIA) of MSW disposal options, including scoping, checklists,
matrices, qualitative and quantitative models and decision-support systems. Rapid Impact Assessment Matrix (RIAM) is a partially
new method which is particularly advantageous over others as it provides a transparent and permanent record of analysis process
at the same time organizing the EIA procedure, which in turn considerably reduces the time taken in executing EIAs. Using this
method, the EIA has been carried out on different MSW disposal options including present landfill, composting, recycling, sanitary
landfill and incineration in Mashhad (northeast of Iran) and it has been found that the sanitary landfill is the best recommended
option under the existing circumstances. The EIA results show that the most important negative impact of the landfill operation is
leachate leakage through layers which can lead to groundwater pollution. To mitigate this effect, the Industrial Waste Evaluation
Model (IWEM) of United States Environmental Protection Agency (USEPA) was used to assess the possible risks associated with
different types of liners. The results show that the single liner is the best alternative among lining options which can provide
protective conditions against leachate seepage in Mashhad’s landfill.