Running water would be simple to set up in his trailer.
Just get a prefab shower pan from home depot ($35), pop a hole in the floor for the drain, get a 50 gal. water drum ($20), and an electric water pump ($35-$100, depending on which one you get) some pvc pipe and fittings, and a cheap shower head ($20). The kind with the hand wand are the most handy. Showers make camping ten times more enjoyable. It would take up maybe 8 sq feet with the drum inside the trailer. Less if you had the drum outside, which is nice because if you use a black drum, the sun will warm the water up.