We live on Long Island and we were camping at the beach before Hurricane Sandy hit last fall. We were going to leave Sunday night but got evacuated Sunday morning with the storm set to hit Monday evening. It was my brother's first time out in his new camper and his first experience using the built in black tank sprayer. We had a FHU site. As you can imagine, we were in a bit of a rush. My brother brought his TT to my driveway for the storm.
About a week or two later my brother stopped by to check on the TT. I don't know why, but for some reason he knelt down by the sewer cap and took it off. He got a nice dose of gray/black water before closing the valve to shut it off.
In his rush to evacuate, he never closed the valves after he was done dumping.