New construction methods have been developed primarily in Europe and Japan for underground pipeline work. The new methods, known as trenchless techniques, are primarily used when existing underground pipes can be rehabilitated to extend their useful lives or when the disruption to a community from conventional underground construction techniques is unacceptable. Trenchless techniques require only minimal or no excavation. Trenchless renovation techniques include inversion lining, sliplining, and spraying methods. Trenchless techniques have also been developed for replacing existing pipes with new pipes of the same or larger diameter along the same alignment and for new pipelines along new alignments. Several trenchless techniques have been available in the U.S. for several years and more techniques will enter the U.S. market in the next several years.