From Inspection to Action: Seven Years of North Texas Municipal Water District’s Multi-Sensor Inspection Outcomes

In 2016, the North Texas Municipal Water District (NTMWD) launched a 10-year Condition Assessment Program (CAP) to evaluate the state of its critical wastewater infrastructure. This paper presents the methodologies and key findings from the first 7 years of the program (FY 2017–FY 2023). The CAP encompasses a comprehensive assessment of large-diameter gravity interceptors, manholes, and force mains using advanced multi-sensor inspections to establish baseline condition scores for future benchmarking and evaluation. By the end of FY 2023, the program had inspected approximately 593,753 linear feet (LF) of large-diameter gravity pipelines and 761 manholes. The ongoing FY 2024 phase includes inspections of an additional 96,789 LF of gravity lines, 14,329 LF of force mains, and 27 manholes. Based on the observed conditions, each asset is assigned a renewal action such as replacement, rehabilitation, point repair, operational and maintenance (O&M) work, or re-inspection. Manholes receive similar recommendations, including replacement, lining, point repairs, O&M work, or re-inspection. To prioritize future inspections and re-inspections, a risk-based assessment was conducted. This process incorporated historical inspection data to evaluate each asset's likelihood of failure (LOF) and consequence of failure (COF). Using Innovyze InfoAsset Planner software, NTMWD developed a wastewater model of its conveyance system, assigning a total risk score to each asset by multiplying the LOF and COF scores. The results of this analysis have been used to update NTMWD's 10-year work plan. This paper will demonstrate the significant value of understanding the condition of a wastewater collection system, which extends beyond financial considerations. For NTMWD, these cleaning and inspection efforts have not only restored conveyance system capacity, potentially deferring or eliminating capital improvement projects (CIP), but also empowered the District to make proactive, data-driven decisions that prioritize risk and maximize system efficiency.