  We study impurity scattering in the normal and d-wave superconducting states
of line nodal semimetals and show that, due to additional scattering phase
space available for impurities on the surface, the quasiparticle interference
pattern acquires an extended character instead of a discrete collection of
delta function peaks. Moreover, using the T-matrix formalism, we demonstrate
that the conventional behavior of a scalar impurity in a d-wave superconductor
breaks down on the surface of a line nodal semimetal in the quasi flat band
limit.
