Methods Of Sludge Disposal What happens to the sludge that is produced after the wastewater passes through the sewage treatment plant? Sludge consists of human faeces and other organic matter. It also has large amounts of water and needs to be thickened so that it can be transported easily and used as compost in farmlands. There are three methods to do so. Sludge may be … [Read more...] about What Are The Methods Of Sludge Disposal