In the wake of the recent explosion in Roseland, a flow of unidentified contaminants –– black, oily, and smelling like asphalt –– has made its way down the Tangipahoa River and is visible at least as far downriver as Ponchatoula. Poston estimates that it takes about 30 hours for water to travel the 25 river miles from Roseland to his campground. By Wednesday, the black gunk was readily visible at Lee’s Landing, less than 10 miles from Lake Pontchartrain. The LDEQ inspector who responded to the explosion described “fire water/oil/chemicals observed escaping outfalls from facility…material observed in Tangipahoa River,” according to the incident report filed that day. Path of the Tangipahoa River: From Roseland to Lee’s Landing.