I drove vaccum tankers for 3 years hauling wastewater and anything esle non hazmat. I loved that job should have never left it. I cant really give you any advice on the hazmat since i never pulled it. But with the wastewater make sure you are empty at the dump. Cuz i have left alittle water in the tank and the next day in the winter my valves would be frozen shut. Have to get the torch out to heat them up to get them to work. Or we would just leave them open over night and stick a 5gal bucket under them.

Well you know going down is like hitting the thrusters in a rocket ship. And you know they always put a sharp curve, stop sign, or red light at the bottom of the really slippery slopes.