Rachelle:—There are different kinds of sludge Im sure. But if your talking about the kind that would be found on a plumbing forum, it is whats left after sewage has been treated at the local treatment plant. It used to be spread on orange groves and other vegetable crops as a fertilizer. It has since been decided by the EPA that it is a toxic substance, and must be buried in the landfills of this country….Bud…What is sludge made of?
Rachael,Sludge can also be settlement of particles in the water supply. Turbidity (suspended matter) will settle on the bottom of a tank while the water is still. Take a glass, fill it from the tap, pick up a small amount of dirt and shake the glass. You will see a cloudy mixture, let ti settle for a few minutes and sludge will form on the bottom of the glass. The same thing happens in a water tank. Add to what Bud said and you have the whole picture. Why is it so? Mossy: What is sludge made of?