I'm sure there are a lot of other people that are tempted to do a roadside dump. All it takes is one person passing by with a cell phone, snapping a picture or taking a vid with the license plate visible, and that's a conviction right there.
A few years ago, when I was shopping for a TT, one guy selling his rig did exactly that -- he had a remote control system to allow him to open the gate valves on his rig from inside his truck. This way, he could pull over on a rural road, open the valves, then get going before anyone discovered what happened. Problem was that he let 'er rip right in front of a Texas DPS officer (DPS is equivalent to the California CHP.) The starting fine was $3500, and I think he also spent a stretch in the county pokey too.