Just read an article by a women who runs/owns the hydro-electric power plant in Lawrence Kansas. They make power for 1,500 homes off a pass through system with a tiny little dam. If you saw it you wouldn't think there was enough drop to make it work. The plant is over 100 yrs. old and with new generation turbines/generators they crank out a lot of power from the slow lazy Kansas River.
Now this lady is saying why the heck don't city sewer plants generate electricity? Most plants let treated water glide down a slope into a river or stream. She says any time there is water falling, we are wasting cheap energy. There are now small water turbines for intermittent and small applications that could be in the outflow stream, claiming a bit of energy and reusing it for the many pumps, paddles and control system. Cities water treatment outflow are rivers, and could generate much and in some cases more than needed to run the operation.
Next time you speak at a city forum, suggest they take a look at this, or next time you face a water price increase tell them about this, it could save money, and make clean energy out of poo.