Combined Sewer System Modeling Analysis
HydroAnalysis developed and applied a model to analyze the City of Fitchburg’s combined sewer system. Fitchburg’s combined sewer system collects both sanitary sewage and stormwater runoff and occasionally discharges combined sewer overflows (CSOs) during large storm events, polluting receiving waters. The purpose of the modeling and analysis was to improve CSO control and support restoration of the Nashua River receiving water. We applied the U.S. EPA Storm Water Management Model (SWMM) to model the Fitchburg sewer system by simulating the runoff of rainfall from the land surface and into the combined sewer system and the subsequent flow of combined sewerage within the sewer system pipe network (over 20 miles in length). HydroAnalysis developed, calibrated, and applied the Fitchburg sewer system model in coordination with the City of Fitchburg and under oversight of EPA Region I and Mass DEP.
This project was completed under subcontract to Dufresne-Henry-Inc.