Yes, it is called sewage and is in a seperate holding tank on the RV or camper. When you "dump" your holding tanks in to the septic well at the campground, you always dump the sewage first and then the grey water. This way the grey water rinses the hose for you, and makes the whole process cleaner.
Some pop up campers don't have a toilet, hense no sewage holding tank. But they still need to dispose of their grey water. That is what this thread is about.
Again, I believe there is a pumpout well on the trailer hookup/disconect driveway near the enterance. I can be wrong, but it wouldn't hurt to call the front desk.