Every year across Canada, billions of litres of clean rain and groundwater is unnecessarily discharged into sanitary sewers and treated at sewage treatment plants. This excess water in sewers, referred to as Inflow/Infiltration (I/I), results in significant costs for governments, which are passed on to taxpayers.
Sewers that collect excess I/I need to be replaced more often, limit the potential for new and expanding development in Canada’s urban areas, and increase the risk of flooding and environmental damage. The impacts of climate change, which include increased risk of extreme rainfall events in many regions of the country, heighten the need to address the problem of I/I.
A new report from Norton Engineering Inc., the Institute for Catastrophic Loss Reduction (ICLR) and the Standards Council of Canada (SCC) provides a basis for developing a National Standard of Canada (NSC) to help address this problem for existing communities across the country.
Developing an Efficient and Cost-Effective Inflow and Infiltration (I/I) Reduction Program discusses methods that can be applied for efficient, effective programs designed to address I/I in existing sewer systems. The report was supported by an expert stakeholder committee and a national consultation process that engaged municipal, building, development, insurance and engineering experts from across the country.
“Governments have been investing in I/I reduction studies and programs for years in Canada, but we don’t seem to be getting ahead of the problem,” said Barbara Robinson, President of Norton Engineering. “We need to develop a ‘modern’ approach to I/I reduction, which considers all of the complexities of the issue, including contributions by private-side sewers. This document is intended to provide guidance to municipalities, consultants, elected officials and others to help implement long-term I/I programs, which consider reducing I/I risk for the life of the sewers, at reasonable cost.”
This publication follows the 2019 report, Reducing the Risk of Inflow and Infiltration (I/I) in New Sewer Construction, which is providing the basis for a new National Standard of Canada to be developed by Bureau de normalisation du Québec (BNQ).
“Flooding of homes during intense rainfall events continues to be a major cause of insured and uninsured property loss across Canada. Evidence suggests that many older communities, with high rates of I/I, are particularly vulnerable to flood impacts. Development of effective programs to management I/I in existing subdivisions will make a significant contribution to reduction of urban flood risk across Canada,” said Paul Kovacs, Executive Director of ICLR.
“The impacts of climate change are already being felt across Canada, and we can expect that intense rainfalls that cause urban flood events will increase under changing climate conditions. Flood-related disasters are already causing billions in property damage, lost productivity, and mental-health impacts to Canadians,” said Chantal Guay, CEO of SCC. “Reducing the leakage of clean water into underground sewers is critical to ensuring that our sewers have sufficient capacity to absorb excess water during heavy storms. This new report provides municipalities valuable step-by-step guidance on tackling I/I in an effective and cost-efficient way. SCC is proud to partner with ICLR and Norton Engineering to advance this important work.”
About Norton Engineering Inc.
Barbara A. Robinson, M.A.Sc., P.Eng., President of Norton Engineering Inc., has been a professional engineer specializing in all aspects of sewer systems for 31 years. Norton provides boutique engineering services to dozens of municipal governments across Canada, as well as provincial and federal governments and agencies, assisting them with finding solutions to the issue of I/I in both existing and new sewers. One of Norton’s focuses has been to critically examine the guidelines, standards and legislation that govern how sewers are designed, constructed, inspected and accepted, with a view to reducing long term I/I. Barbara chaired the national CSA committee that developed “CSA Z800-18: Basement Flood Protection and Risk Reduction Guideline” (June 2018).
For additional information, visit nortonengineeringinc.ca
About the Institute for Catastrophic Loss Reduction
Established in 1997 by Canada’s property and casualty insurers, the Institute for Catastrophic Loss Reduction is an independent, not-for-profit research institute based in Toronto and at Western University in London, Canada. The International Council for Science designated the Institute as an International Centre of Excellence in integrated research on disaster risk. The Institute is also a founding member of the Global Alliance of Disaster Research Institutes. The Institute’s research staff are internationally recognized for pioneering work in a number of fields including wind and seismic engineering, atmospheric sciences, water resources engineering and economics. Multi-disciplined research is a foundation for the Institute’s work to build communities more resilient to disasters.
For additional information, visit iclr.org
About the Standards Council of Canada
Established in 1970 as a federal Crown corporation, the Standards Council of Canada (SCC) is Canada’s voice on standards and accreditation on the national and international stage. SCC works closely with a vast network of partners to promote the development of effective and efficient standards that protect the health, safety and well-being of Canadians while helping businesses prosper. As Canada’s leading accreditation organization, SCC creates market confidence at home and abroad by ensuring that conformity assessment bodies meet the highest national and international standards. SCC advances Canada’s interest on the international scene as a member of the International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC) by connecting thousands of people to global networks and resources, opening a world of possibilities for Canadians and businesses.