Looking down into a retention basin from the tank scaffolding--the basin contained oily waste-I was shocked by how beautiful it was--the way the sky was reflected back at me.  On the 5th rung a bird made a nest.  I found myself wondering if the bird too was confused by the optics of the waste, and thought perhaps it had nested high in the sky, safe from predators--instead of 4 feet above a hazardoue waste pit.