Probably some dickwad washing his luxury sports vehicle in his driveway. Or pressure washing his house. I saw a neighbor of mine doing that a month ago or so. He was washing his Mercedes with a bucket full of detergent and his hose. I mentioned to him that the effluent goes directly from his driveway into the storm sewer and then into the river. He just looked at me like I was from outer space. You know they educated the school children with the yellow fish program, maybe they should do that with the BIG kids.