Sludge degritting is mainly used in cases of poorly performing liquid stream processes. Devices used for washing and dewatering grit slurry are used to remove grit from sludge for less cost than installing new liquid stream grit removal processes. Conventional cyclone/classifiers and induced vortex systems are used for this process. When degritting primary sludge, sludge solids must be pumped at concentrations of 0.5% to 1% for the process to function properly, requiring frequent pumping of the sludge or an addition of dilution water. The grit removed from primary sludge degritting has high organic content which requires a high degree of grit washing.