Fort Worth Interceptor Condition Assessment Leads to Improved Asset Management and Long-Term Sustainability

The City of Fort Worth Water Department has undertaken a comprehensive program utilizing multisensor inspection (MSI) technology to inspect its entire large-diameter sanitary sewer interceptor system. As the program approaches 50% complete, this paper presents the techniques used for condition assessment and how the condition of the pipes and location of debris were translated into estimates of remaining useful life, efficiently targeted large-diameter cleaning, and repair/replacement recommendations for long-term asset management. Assessment techniques included laser profiling, sonar, and high-definition televising. The Fort Worth project is considered one of the largest multisensor interceptor condition assessment projects in the world. The interceptor system contains 262 miles of pipelines ranging from 24 in. to 96 in. diameter. Original pipe materials were primarily reinforced concrete with some vitrified clay. More recent pipe materials were fiberglass and plastic direct burial and liners. To date more than 50 different pipe specifications have been identified and included in the remaining useful life (RUL) matrix. Expectations based on age and pipe materials in many cases were contradicted by actual measurements of pipe wall loss and condition. Utilizing the RUL Matrix, measured remaining wall thickness, and calculated deterioration rates per year, the Fort Worth Water Department is able to identify pipe segments that require near-term remediation and optimize future pipe segment inspections.