Years ago, when I lived in Cleveland, the city discovered, on opening day of the city swimming pools, that when the maintenance crews had painted the pools before opening, they didn't do the least amount of clean up first. They just painted over EVERYTHING - dirt, leaves, paper, etc.

They even painted over BROKEN GLASS. Apparently it had been real popular for people to throw empty bottles over the fence, and hear them smash into the empty pools. Every pool had lots of broken glass on the bottom, and the painting crews just painted right over it. It seems like that would be such a pain in the ass, that it would be easier to take 15 minutes and sweep it out first, but those losers couldn't be bothered.

It was a big deal in the media, and pools opened a few weeks late, as they scraped the bottoms and repainted.