"You might not expect much good environmental news to come from sewage plants, but, believe it or not, there is some on occasion. And in one case, that good news even involves thriving salmon. ...Peter Baranyai directs Wastewater Operations for the Sanitary District of East Chicago, Indiana. The plant's effluent channel looks like a natural stream and has apparently fooled wilflide into thinking so, too."
"Salmon Spawning In Sewage Plant"
Source: Environment Report, 12/17/2009