Why do we need to sort out recycling at the transfer station when curbside does zero-sort?

The Gleason Road requires that recyclables are pre-sorted such that we don’t have to pay a middleman to sort them. Zero sort is very expensive, if this cost was passed on to us, it would have to be passed onto the users.  It is very important that all users that use our recycling center pre sort their recyclables. It only takes one bad actor to cause a whole container to become contaminated.  If this happens, we will be charged the same price trash cost (instead of receiving revenue for the commodity). This cost will need to be recovered somehow.