Answer from last post:

ANSWER to yesterday's photo question. . .

There is a little man made creek/ water fountains at one end/ and waterfall at this end. So that is the water from the waterfall in the little park next door to our building. The gardner puts a soap like solution in it to keep the moss/algae from forming since it is not a natural river bed. It makes the water look ridiculous but interesting for a photographer walking by. . .

Thanks for all your creative answers/guesses. Rune E. was the almost right -- it had nothing to do with a sink tho. . . Ü I suppose you could call the disinfectant soap. . .