At 5'9, 240 lean pounds is most likely extremely difficult, if not impossible without some chemical help.
At 6', I've been at 240 and relatively lean but my routine and diet were completely in check. I wasn't missing work outs, didn't skip a meal and made recovery a priority (In bed for 8 hours at least, including weekends, no booze fests with buddies, every food had a specific purpose...).
My routine was geared to build muscle specifically and I wasn't doing any cardio. I couldn't break 240 myself and maintaing it was an exercise in self control above and beyond my capabilities for more than a few weeks after achieving the goal.
I'm most comfortable around 225-230 myself, not that I advocate slacking. This still requires consistent effort and diet to maintain lean but with some leeway.
Point being, we all have natural limits. You may be genetically gifted and able to hit a lean 240 at 5'9", I'm not pissing on your candles, but know it is unlikely.