Fates of TRB and pB10 plasmids in synthetic leachate were studied for 2 years. Two years is composed of 3 phases. During Phase II, TRB decreased & pB10 increased. pB10 plasmid survived and increased even after two years of the study period. EC50 values and pyrosequencing showed changed in microbial community. Leachate can select both microbial community and genes depending on its properties.