You will get fined if they find you draining any tank on the ground. This is a quote from another site:“THE RULE”
Never, never, never dump grey or black water on the ground….especially black water! Black water is raw sewage is a bio-hazard. I’m reminded of the time I was staying in a park and someone dumped their black tank water on the ground. When management “caught wind” of this…they called 911 because they are required to do so by law. Well, about 5 snappy minutes later a HAZMAT team arrived on the scene, all dressed up in their HAZMAT gear, they cordoned off the area and evacuated part of the park so they could clean up the “bio-spill”.
Think about things before you do them make life easier not harder.