AC Pipe in North America: Rehabilitation/Replacement Methods and Current Practices

Asbestos cement (AC) pipe was first introduced in North America in the late 1920s and became a common choice for potable water main construction from the 1940s to the 1970s. The use of AC pipe was largely discontinued in North America in the early 1980s but AC pipe is still a significant portion of the water distribution systems in many North American cities. As the pipes deteriorate and fail to meet service requirements, appropriate rehabilitation/replacement methods need to be determined. This paper summarizes survey data on the rehabilitation/replacement methods for AC pipes provided by 19 water utilities in the United States and Canada. The paper also reviews current available rehabilitation/replacement methods to provide some background of the current practices used by the utilities. The survey indicates that trenching is the main method used to repair, rehabilitate, and replace AC pipes. Cost was cited as the main reason for utilities to choose a particular repair/rehabilitation/replacement method. Although most of the rehabilitation/replacement methods have potential social and environmental effects because of possible release of asbestos fibers, the effects were generally not given high priority when selecting methods for renewing AC pipes.