Process for Evaluating Sanitary Sewer Pipe and Manhole Condition Assessment Data

To effectively manage sanitary sewer system assets, utilities should collect condition data, analyze the data, and make decisions on what to do with each asset based on this information. Infrastructure owners should know the condition of their systems and have processes that support their program activities. Without condition and performance knowledge, appropriate preventative measures cannot be properly planned and implemented. In addition, regulators are expanding their push for better condition assessment practices through programs such as Capacity, Management, Operations, and Maintenance (CMOM) and in enforcement actions at both the state and federal levels. This paper describes analysis of manhole and sewer pipeline data to develop estimates of infiltration and inflow (I/I) and to prioritize each asset using a risk-based approach for prioritizing improvement needs. Defect I/I rates are necessary for conducting a full cost-effectiveness analysis. Specifically this paper will address the following: (1) Risk-based approach to condition data analysis. (2) Guidelines for assignment of defect I/I rates.