My ac drip pan in my apt has standing water in it, the drain is not clogged. Is this normal and healthy?

The way the ac ceiling unit is made, the drain pipe is a little over the base of the pan. So there is always water sitting in it and it is a disgusting mess. My apt maintenance says its normal for the ac units here to have water sitting in them. I always thought it was supposed to stay dry or drain completely. Am I wrong thinking there shouldn't be any buildup of water in it at all? Or are they pulling my leg and not wanting to fix the problem?