Sewer backed up by large...

[Father Kit Cool Gun Garth]

  Pooh! 

[Linn Keller, SASS 27332, BOLD 103]

... not surprised at all ...
... you'd be surprised at the stuff washes into a sewer plant.

The constabulary called down one dark night and said some Jack Doe robbed a convenient store as they were heading to the car with the day's receipts, supposedly they stashed the canvas bank bag in a storm sewer and nothing was there when they pulled the cover and looked ... it had been raining, enough storm flow to wash it downstream ...

The primary operator (dead several years now) was very, very attentive to the bar screens, and a year later, over a confidential beer, admitted if he'd found the bank bag, he never would have called the cops to report it found.

(It had never been donated to the sewer after all, they found it under the perp's mattress)