Currently, sewer maintenance (repair, replace and rehabilitation) is conducted largely in a responsive fashion, which is usually driven by sewage spills and complaints. Recently, many sewer system owners have started to implement system-level sewer condition assessment, in order to conduct preventative maintenance and rehabilitation. However, the only technology available is based on direct flow measurement, which can be erroneous due to the complex sewer environments and limitation of the flow measurement technologies. Since making such large investment decisions based on data from a single data source can introduce significant systematic risks, it is crucial that an alternative and independent sewer assessment approach is available.
This I-Corps project aims to develop chemical markers in sanitary sewage for rapid and system-level sewer deterioration condition assessment. A previous NSF-funded project discovered that total nitrogen (TN) in sanitary sewage exhibited characteristic and stable daily flux pattern, and changes in TN concentration due to rainfall derived infiltration and inflow (RDII) can reliably estimate RDII level and hence sewer deterioration severity level. The flux stability of TN and its ability to predict sewer deterioration represents a new sewer condition assessment strategy that can complement and augment the current approaches.
