I remember being in Biloxi in 1989 (before Biloxi was Biloxi, which it isn't so much anymore), and they were telling us then not to go in the water with any open cuts because of sewage and whatnot in the water. If memory serves, they were telling us it was left from CAMILLE 20 years earlier, and was just trapped by the barrier islands from ever getting washed out to sea.
Incredible. Left over from Camille? Was it industrial waste? Seems like the risk would have been cancer rather than infection.