Pipe Failure Risk Statistics from over Ten Million Pipe-Years of Records

When planning water main replacement programs, pipeline engineers make decisions on which pipes to address using failure risk factors. Pipe material, diameter, length, age, and previous failure history frequently play a role in these decisions. Despite their intuitive and ubiquitous use in making these critical decisions, the actual relationship between these factors and pipe failure rates is not well-documented. Over the past 5 years, a research program led by the University of Waterloo has assembled a large and diverse database of pipe failure records. With contributions from six utilities in North America, Europe, and Asia, this database covers over 10 million pipe-years of records. The records include over 500,000 pipe segments spanning over 30,000 km (over 18,000 mi) of pipe with detailed records of over 150,000 pipe failures. This paper presents broadly applicable statistics regarding pipe failure risk predictors, drawn from this database.