Ok. Technically Sewage Sludge is a phrase.

The other day I was talking about cofiring. And I discovered that one of the fuels they cofire alongside coal is sewage sludge.

What is sludge?

Up to 95 percent is water. But it starts as wastewater, which is a mix of food, paper, diapers, plant mater, feces, condoms, sanitary napkins, paints, pesticides, bacteria, pathogens, pharmaceuticals, sand, metal particles, road salt, insects and gases.

I think I would prefer 100% coal.