Rehabilitation of Prestressed Concrete Cylinder Pipe—A Utility Perspective

This paper describes Calleguas Municipal Water District's [Calleguas] recent rehabilitation activities on Prestressed Concrete Cylinder Pipe [PCCP]. Calleguas annually supplies 1.233 x 10⁸ m³ [100,000 acre-feet] of imported State Project Water to Ventura County, California through Calleguas' 208 km [130 miles] of transmission pipelines. Forty kilometers [25 miles] of these pipelines are PCCP, in nominal sizes ranging from 1.22 m [48″] to 1.98 m [78″], with installation dates between 1964 and 1982. In 1997, a catastrophic break occurred in one location on a 1.68 m [66″] pipeline. After conducting immediate repairs to place the line back in service, Calleguas initiated a program of evaluation and rehabilitation to ensure the structural integrity of the PCCP lines, which are the backbone of Calleguas' distribution system. This paper will discuss the types of rehabilitation and repair activities performed by Calleguas since 1997, including pipe replacement, steel cylinder lining, and carbon fiber lining. Each has advantages and disadvantages, and each has its place in a program for PCCP rehabilitation.