The extent of infiltration also correlates with the condition of again sewers. RDII is the main cause of sanitary sewer overflows (SSO) to Rainfall-derived infiltration and inflow (RDII) is the increased portion of water flow in a sanitary sewer system that occurs during and after a rainfall as a source of operating problems in sanitary sewer systems.
This screenshot of the EPA SSOAP Toolbox (Version 2.0) shows the relationship flow of the following six tools that can be used to help analyze capacity and condition of a sanitary sewer system: 1) Database Management Tool, 2) RDII Analysis Tool, 3) RDII Hydrograph Generation Tool, 4) SWMM5 Interfacing Tool, 5) SWMM5 Tool, and 6) Condition Assessment Support Tool.
