  We consider the one dimensional symmetric simple exclusion process with a
slow bond. In this model, particles cross each bond at rate $N^2$, except one
particular bond, the slow bond, where the rate is $N$. Above, $N$ is the
scaling parameter. This model has been considered in the context of
hydrodynamic limits, fluctuations and large deviations. We investigate moderate
deviations from hydrodynamics and obtain a moderate deviation principle.
