We present a benchmark solution for one-dimensional porous media with heterogeneity involving two soils separated by a sharp interface. A similar problem was discussed previously by other researchers; however, only a diffusion term was considered in their models. The proposed solution allows the inclusion of advection terms in a limited way. This solution is useful in the verification of more complex numerical models of multiphase flow developed for general applications involving heterogeneous aquifers. A derivation of the semianalytical solution for heterogeneous porous media is presented and its existence and uniqueness are discussed. A computationally efficient algorithm and several computational results are presented.