Abstract. The treatment of porous media with the BEM exhibits some problems, which are common also for the Finite Element Method, but also some BEM specific ones. The three main problems are: First, the multiphase system requires four degrees of freedom per node, leading to large matrices even for small problems. Since the BEM matrices are densely populated, this makes the method prohibitive for large problem sizes. Second, due to the different physical nature of the degrees of freedom the matrix entries vary over several orders of magnitude. Third, the fundamental solution of poroelasticity is computationally expensive.We present a FM-BEM that circumvents those points: The Chebyshev interpolation-based FMM significantly reduces the memory consumption of the system matrix and thus allows for larger problem sizes to be treated. As well, it requires fewer evaluations of the fundamental solution. To employ an iterative solver, the use of a transformation of the material data is mandatory.