  We present the results for $B_K$ calculated using HYP-smeared staggered
fermions using lattices generated by the MILC collaboration using the asqtad
staggered action. We have done the calculation on 8 ensembles of these
lattices, including three different lattice spacings ($a=0.12, 0.09, 0.06$ fm).
We fit the data to forms based on those predicted by SU(3) mixed-action
partially-quenched staggered chiral perturbation theory. Our preliminary result
is $ B_K(\text{NDR},\mu=2\text{GeV}) = 0.528 \pm 0.011 \pm 0.048 $, where the
first error is statistical and the second systematic. The error turns out to be
larger than that from an analysis using SU(2) chiral perturbation theory.
