Well, this experience certainly deserves the insightful remarks it has harvested, as well as the egregious puns.
Here's another clean-up memory that I had repressed when I was first posting this thread. It has to do with cleaning up the floor of the locker. There was still a half inch of liquid and soggy paper floating around when the plumber left, and my wet-dry shop vac was at my job site 20 miles away. So I shoveled as much as I could, bit by bit into a 5-gallon mud bucket. Then I sopped up the rest with several rolls of paper towels. Then I got some lemon scented clorox and mopped everything clean, carefully draining the mop into the sink around the corner which was draining into the locker where the pump had been. It took me several trips to realize that I was losing ground as the liquid level on the locker floor inexplicably rose. Dah!
After several hours of heat and fan the surfaces down below appear drier.