This paper utilises the modified Folchi method to assess the environmental impact of coal washing plant, Alborz Sharghi, North-east Iran. In this study, the number of factors designed in the method was slightly modified by focusing on the environmental impact of coal washing operations. In addition, few other factors were designed and added to the previous factors. Then, twenty-one values of environmentally impacting factors from the study area and a case with standard amounts of effects were calculated. This method was conducted by forming an assessment matrix in which one dimension is the environmental components and the other one is impacting factors to estimate the environmental problems arising from the impacting factors of both cases. Comparison of the results of two cases shows that the amount of contamination produced by the plant, especially for components including air quality, agriculture and area landscape is significant.