Resurrecting an Abandoned Potable Water Pipeline System

The Diablo Water District (District) is located in the eastern portion of the San Francisco Bay Area in Northern California. This part of Contra Costa County has experienced several recent periods of rapid growth; however, when the United States economy began to enter a recession in 2008, one of the larger developments within the District’s sphere of influence and future service area, the Delta Coves development, decided to postpone construction of its planned 494 single family houses after spending over 2 years performing site grading and installation of underground utilities. This resulted in over 50,000 ft (15,240 m) of installed 8-in. (200 mm) to 16-in. (400 mm) PVC water mains, plus related distribution infrastructure, being abandoned in-place without any prior inspection or acceptance by the District. In 2014, the developer became interested in completing the development. This paper describes the process and methods used by the District to understand, repair, and eventually assume ownership of these assets, including various methods of inspection, analysis of PVC pipe, and the use of ice pigging prior to final disinfection and testing for acceptance.