The feasibility of using pipelines to transport waste materials, and to develop a reliable procedure for the design of such pipelines was studied. A series of laboratory and pipeline tests was performed. Digested sewage sludge and fly ash were chosen as representative materials for the tests. Both materials, sludge because of its fibrous nature and fly ash because the particles are very fine, were transported in homogenous flow in the turbulent regime. Samples taken from the top and the middle of the pipe test sections confirmed this. These materials, individually and in various combinations, were tested at various velocities in 1/2-inch, 12-inch, and 16-inch pipe test sections, for a number of solids concentrations. Digested sludge, fly ash, and fly ash/sludge mixtures can be successfully transported by pipelines. (WRSIC abstract)