Teach everyone how to print front and back on all printers in use.
Set printers to print automatically in duplex mode with draft ink setting for copies of working drafts
Make this printing preference standard for all print jobs.
Reason 1: too many copies of too many documents in working draft stage are printed on front side only because it takes some thought and effort to set up duplex printing for each job.
Reason 2: too much paper is wasted by printing on front side only for working drafts.