  We study the capabilities of the short baseline neutrino program at Fermilab
to probe the unitarity of the lepton mixing matrix. We find the sensitivity to
be slightly better than the current one. Motivated by the future DUNE
experiment, we have also analyzed the potential of an extra liquid Argon near
detector in the LBNF beamline. Adding such a near detector to the DUNE setup
will substantially improve the current sensitivity on non-unitarity. This would
help to remove CP degeneracies due to the new complex phase present in the
neutrino mixing matrix. We also study the sensitivity of our proposed setup to
light sterile neutrinos for various configurations.
