  We present a numerical study of collisional transport in a tokamak pedestal
in the presence of non-trace impurities, using the radially global $\delta f$
neoclassical solver PERFECT [M. Landreman et al. 2014 Plasma Phys. Control.
Fusion 56 045005]. It is known that in a tokamak core with non-trace impurities
present the radial impurity flux opposes the bulk ion flux to provide an
ambipolar particle transport, with the electron transport being negligibly
small. However, in a sharp density pedestal with sub-sonic ion flows the
electron transport can be comparable to the ion and impurity flows.
Furthermore, the neoclassical particle transport is not intrinsically
ambipolar, and the non-ambipolarity of the fluxes extends outside the pedestal
region by the radial coupling of the perturbations. The neoclassical momentum
transport, which is finite in the presence of ion orbit-width scale profile
variations, is significantly enhanced when impurities are present in non-trace
quantities, even if the total parallel mass flow is dominated by the bulk ions.
