A number of U.S. cities have sewage collection systems dating back over 100 years. Some of the original brick sewers built in the 19th century are still in service, as are systems of clay pipes with open joints that were constructed at the turn of the century. All structures wear out in time, and pipelines are no exception. Because pipelines are underground, signs of wear are not readily apparent until a failure occurs. Failures start with cracking, lateral deflection, crown sag, offset joints, deteriorating mortar, and exposed reinforcing. Most of the community sees only the inevitable result of prolonged neglect–cracked pavement, collapsed streets, back-up sewers, or local flooding. Actually, however, the community is paying a heavy price in diminished capacity and increased infiltration and inflow long before these dramatic failures occur.