Author(s): Yvonne Wai; Shafiqul Islam; Brent Burton
Linked Author(s):
Keywords: Wet Weather Flow; Rainfall Induced Inflow and Infiltration; I&I; SSOs; North Shore Sewerage Area; Metro Vancouver; MOUSE Modelling
Abstract: Metro Vancouver (MV) serves over two million people and comprises 22 member municipalities, one electoral area and one treaty First Nation. MV provides a variety of services to its members, including regional liquid waste collection, transport and treatment. In 2001, MV developed the region's Liquid Waste Management Plan (LWMP) to identify strategies to manage liquid waste effectively and affordably. This plan is currently being updated. One of the major sewerage areas serviced by MV is the North Shore Sewerage Area (NSSA) with a population of approximately 185,000. MV collects separated liquid waste from the three municipalities comprising the NSSA and transports it, via a variety of conveyance structures, to the Lions Gate Wastewater Treatment Plant (LGWWTP). Much of the piped infrastructure has been in use for many decades, with an average age of about forty years, resulting in relatively high levels of inflow and infiltration (I&I) into the collection system. These high levels of I&I can challenge sewage management resulting in sanitary sewer overflows (SSOs). In accordance with the LWMP, MV is seeking to eliminate SSOs associated with storms events of a 5-year return period or less. A hydrologic and hydraulic simulation model was developed using MOUSE software developed by the Danish Hydraulic Institute (DHI). This model was used to investigate different options for reducing SSOs in the NSSA. This paper presents an overview of the model development, calibration, verification and scenario simulation, outlining the special challenges in using this model to represent extremely steep, mountainous catchments with relatively limited available measured data. The application of this simulation model in analyzing sensitivity to other factors, such as ongoing climate change, is also discussed in this paper.
Year: 2009