Software Tool Helps Reduce Levels of Rainfall-dependent Inflow In Sewer Network

The Region of Peel in Canada has chosen InfoWorks CS from Wallingford Software (UK) as a key tool in its drive to reduce levels of rainfall-dependent inflow and infiltration (RDII) in the sewer network.
"We went through an extensive evaluation process, looking at different products, and came to the conclusion that InfoWorks CS was the best to meet our requirements," says Supervisor for Capital Programming and Infrastructure Management, Imran Motala. "Out of the various
commercial modeling packages available, InfoWorks CS has the best ability to model the physical characteristics of inflow and infiltration
associated with rainfall as well as the detailed properties of the modelled system. This, in combination with the strong scenario manager and independent GIS platform, provides the best modelling tool that meets Region of Peel`s project needs and long-term requirements."
The Region of Peel is situated in southern Ontario, west of Toronto, and comprises the cities of Mississauga and Brampton and the town of
Caledon. Its population of about 1.1 million is growing rapidly and is forecast to reach 1.5 million by 2031, which places increasing demands on the sewer network. Extensive investment is under way including expansion and upgrading of the two wastewater treatment facilities as part of the region´s aim to have one of the world´s most innovative and technically-advanced water and wastewater systems. Peel operates and maintains more than 2,500km (1,550 miles) of sanitary sewer mains and 34,500 manholes as well as providing sanitary sewer services to the property-line for all connected residential and commercial properties
within the region. InfoWorks CS will be used for dynamic modelling and hydraulic inflow and infiltration analysis for the development of plans
to improve the wastewater network. Consultant Earth Tech has recently completed building, calibrating and validating the model within InfoWorks and is now set to begin the inflow and infiltration analysis.
"Some areas have inflow and infiltration as high as ten times the design allowance," says Imran Motala. InfoWorks will be used in determining the extent of these external flows into the system as
well as differentiating between infiltration from leaks and inflow from unregistered connections.
"It is an old network and we suspect that some areas have indirect connections that should not be there." Use of InfoWorks will enable the engineers to prioritise areas where problems need to be addressed.
"InfoWorks CS has a well-developed RDII module to simulate rainfall-induced inflow and infiltration. Its powerful scenario manager,
data-tracking capabilities and its independent GIS and presentation capabilities make it one of the best modelling packages available today," he adds.
InfoWorks CS is also being used to examine sanitary sewer overflows, with a view to eliminating any that are unnecessary and improving the effectiveness of those that are required during severe rain events. "We suspect that we have certain overflows that would not be activated even following a rain event with a 25 year return period - we would like to abandon those," he says. Use of InfoWorks will enable the testing of a variety of scenarios and the development of storage solutions with real-time controls for the overflows that need to remain in service.