Most of my opinions in this subject and other similar are based on my experiences. For a number of years, I did volunteer work in the local forest and deserts. One of the reasons I stopped doing this was the people in charge of enforcement in these areas.
At one time, I was on the board of directors for a large wildlife group. We did a ton of work out in the Mojave. We were funded by Fish and Wildlife. Our fuel, food, ect.. was all on us. Even though we were doing environmental/wildlife work, we were hated by some BLM, Park Service and Forest rangers. The only reason I can see was, we were human. Not only did they go out of their way to try and stop us, they would do whatever they could to harass. This is not all but, some. Those few were giving all the others a bad name. When we would work on projects with them, they would talk about how people shouldn't be out here.
Back on topic. These individuals are the one's that will cite you. In a single vehicle, you don't get noticed, in a group you may. In a group of motor homes the likeliness is greater. I have never looked at federal regulations but, I would not be surprised if there was not a specification on how much "grey water" your allowed to dump (washing dishes). I have traveled most of the west and some of the mid. When I encounter any of the rangers, I try to strike a conversation. I don't only do this to find out what the regulations are, but to gauge the attitude of the people working there. You would be surprised how some will complain about their fellow workers for either being too strict or too lax on people. If its possible, I lead the conversation with my wildlife group, not off road. If I did, the odds that they would dislike me were greater.