Rainbows in the Lehigh Valley Gorge

[Charlie B]

Todd, very well done. looks like you know your ....stuff   The hydro power plant I operated was right next door to the sewage treatment plant and we became good friends with the superintendent  as well as one of the operators.
    There were large beds lined with sand that the sludge was put on and allowed to dry, then it was placed in a pile and some folks would use it for garden fertilizer.  They also captured the methane gas and used it to run engines that powered the various pumps. 
    I don't have a municipal plant but I do have a septic tank pump truck and a house that is having a tank installed. You could add a truck to the scene that is dumping into the system    
Charlie